当tag事件通知时，返回值中evt.KV.Value断言为*pb.MicroServiceInstance失败

[chenwei113524]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. 通过postman调用修改tag接口
2. evt.KV.Value断言为*pb.MicroServiceInstance失败

Expected behavior 2022-03-03 15:03:04.932 +08:00 ERROR log/lager.go:98 goroutine 306 [running]: runtime/debug.Stack(0x0, 0x0, 0x0) D:/go/go1.16.6/src/runtime/debug/stack.go:24 +0xac github.com/apache/servicecomb-service-center/pkg/log.(*Logger).Recover(0xc000082640, 0x1c4b460, 0xc000d2c2a0, 0x3) D:/go/xxxx/servicecomb-service-center/pkg/log/lager.go:98 +0xf2 github.com/apache/servicecomb-service-center/pkg/log.LogPanic(0x1c4b460, 0xc000d2c2a0) D:/go/xxxx/servicecomb-service-center/pkg/log/logger.go:100 +0x51 github.com/apache/servicecomb-service-center/pkg/log.Recover() D:/go/xxxx/servicecomb-service-center/pkg/log/logger.go:107 +0x5e panic(0x1c4b460, 0xc000d2c2a0) D:/go/go1.16.6/src/runtime/panic.go:971 +0x4e6 github.com/apache/servicecomb-service-center/server/service/event.PublishInstanceEvent(0xc54, 0x1e812fe, 0x6, 0xc0015d49b0, 0x622067e6, 0x162076bc, 0xc00020c240, 0xf, 0xc000508380, 0xc001a9b048, ...) D:/go/xxxx/servicecomb-service-center/server/service/event/instance_event_handler.go:112 +0x609 github.com/apache/servicecomb-service-center/server/service/event.(*TagsChangedTask).publish(0xc0001705b0, 0x2044240, 0xc001071d70, 0xc00020c240, 0xf, 0xc000304320, 0x20, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/server/service/event/tag_event_handler.go:90 +0xa07 github.com/apache/servicecomb-service-center/server/service/event.(*TagsChangedTask).Do(0xc0001705b0, 0x20441d0, 0xc000034050, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/server/service/event/tag_event_handler.go:48 +0xb4 github.com/apache/servicecomb-service-center/pkg/task.(*AsyncTaskService).Add(0xc000212100, 0x20441d0, 0xc000034050, 0x20360f0, 0xc0001705b0, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/pkg/task/service_async.go:85 +0x131 github.com/apache/servicecomb-service-center/server/service/event.(*TagEventHandler).OnEvent(0x2a218c0, 0xc54, 0x1e8160a, 0x6, 0xc0015d49b0, 0x622067e6, 0x162076bc) D:/go/xxxx/servicecomb-service-center/server/service/event/tag_event_handler.go:117 +0x57a github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery.(*KvEventProxy).OnEvent(0xc00020ae10, 0xc54, 0x1e8160a, 0x6, 0xc0015d49b0, 0x622067e6, 0x162076bc) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/event_proxy.go:43 +0xcd github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery.(*Config).AppendEventFunc.func1(0xc54, 0x1e8160a, 0x6, 0xc0015d49b0, 0x622067e6, 0x162076bc) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/config.go:75 +0x5d github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).notify(0xc000736300, 0xc001071bf0, 0x1, 0x1) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:406 +0x152 github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).onEvents(0xc000736300, 0xc001071bf0, 0x1, 0x1) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:394 +0x38b github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).sync(0xc000736300, 0xc001071bf0, 0x1, 0x1) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:208 +0xba github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).handleWatcher(0xc000736300, 0x201b358, 0xc000d3aeb0, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:158 +0x735 github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).doWatch(0xc000736300, 0x6fc23ac00, 0x2044198, 0xc00043a040, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:91 +0xa5 github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).ListAndWatch(0xc000736300, 0x2044198, 0xc00043a040, 0x0, 0x0) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:121 +0x29d github.com/apache/servicecomb-service-center/server/plugin/pkg/discovery/etcd.(*KvCacher).refresh(0xc000736300, 0x2044198, 0xc00043a040) D:/go/xxxx/servicecomb-service-center/server/plugin/pkg/discovery/etcd/cacher_kv.go:181 +0x187 github.com/apache/servicecomb-service-center/pkg/gopool.(*Pool).execute(0xc0007362a0, 0xc00068e030) D:/go/xxxx/servicecomb-service-center/pkg/gopool/goroutines.go:75 +0x82 github.com/apache/servicecomb-service-center/pkg/gopool.(*Pool).loop(0xc0007362a0, 0xc00068e030) D:/go/xxxx/servicecomb-service-center/pkg/gopool/goroutines.go:96 +0x171 created by github.com/apache/servicecomb-service-center/pkg/gopool.(*Pool).Do D:/go/xxxx/servicecomb-service-center/pkg/gopool/goroutines.go:84 +0x1f9

Platform And Runtime (please complete the following information):

Platform

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Runtime

• Version [e.g. Go 1.11]

Additional context Add any other context about the problem here.