panic: runtime error when revocation is done for a user

[0xWaveWalker]

Hi all,

I am using the nats-account-server version 0.8.4. If the server is running while doing a revocation using nsc tool, the nats-account-server stops and throws an error:

2020/11/22 18:44:02.555349 [INF] loading configuration from "/home/ubuntu/natsaccountserver.conf"
2020/11/22 18:44:02.556384 [INF] starting NATS Account server, version 0.8.4
2020/11/22 18:44:02.558303 [INF] server time is Sun Nov 22 18:44:02 CET 2020
2020/11/22 18:44:02.559107 [INF] loading operator from /home/ubuntu/.nsc/nats/something/something.jwt
2020/11/22 18:44:02.564659 [INF] loading system account from /home/ubuntu/.nsc/nats/something/accounts/SYS/SYS.jwt
2020/11/22 18:44:02.568421 [INF] creating a read-only store for the NSC folder at /home/ubuntu/.nsc/nats/something
2020/11/22 18:44:02.569964 [INF] connecting to NATS for notifications
2020/11/22 18:44:02.604849 [INF] connected to NATS for account and activation notifications
2020/11/22 18:44:02.608459 [INF] http listening on port 9090
2020/11/22 18:44:02.609303 [INF] nats-account-server is running
2020/11/22 18:44:02.610130 [INF] configure the nats-server with:
2020/11/22 18:44:02.611052 [INF]   resolver: URL(http://localhost:9090/jwt/v1/accounts/)
2020/11/22 18:45:09.961708 [ERR] The NSC store encountered an error, shutting down ...
2020/11/22 18:45:09.961765 [INF] stopping account server
2020/11/22 18:45:09.962008 [INF] disconnected from NATS
2020/11/22 18:45:09.962037 [INF] stopping http server
2020/11/22 18:45:09.962183 [INF] http server stopped
2020/11/22 18:45:09.962219 [ERR] error closing listener: close tcp 127.0.0.1:9090: use of closed network connection
2020/11/22 18:45:09.962246 [INF] http stopped
2020/11/22 18:45:09.976430 [INF] closed JWT store
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x60 pc=0x7a69ef]

goroutine 10 [running]:
github.com/nats-io/nats-account-server/server/store.(*NSCJWTStore).startWatching.func1(0xc0000ecab0, 0xc0000582a0)
	/Users/waldemarquevedo/repos/nats-dev/src/github.com/nats-io/nats-account-server/server/store/nscstore.go:125 +0x32f
created by github.com/nats-io/nats-account-server/server/store.(*NSCJWTStore).startWatching
	/Users/waldemarquevedo/repos/nats-dev/src/github.com/nats-io/nats-account-server/server/store/nscstore.go:103 +0x2b0

The nsc command I use to do the revocation is: nsc revocations add_user --name simple