Tablets tests are flakky

[dkropachev]

08:32:56  === RUN   TestTablets
08:32:57      tablet_integration_test.go:100: trace should show only one host but it showed 2 hosts, hosts: [127.0.1.2 127.0.1.1 127.0.1.3]
08:32:57  --- FAIL: TestTablets (0.79s)
08:32:57  === RUN   TestTabletsShardAwareness
08:32:58      tablet_integration_test.go:153: trace should show only one shard but it showed 2 shards, shards: [shard 1/sl:default shard 0/sl:default]
08:32:58  --- FAIL: TestTabletsShardAwareness (0.93s)