fix itest re `blockbeat` #472

Job	Run time
lint code	5m 0s
check commits	45m 54s
RPC and mobile compilation check	2m 30s
sample configuration check	59s
cross compilation	31m 51s
Sqlc check	46s
run unit tests (btcd unit-cover)	5m 58s
run windows itest	6m 43s
run unit tests (unit tags="kvdb_etcd")	18m 40s
check pinned dependencies (google.golang.org/grpc v1.59.0)	5s
run unit tests (unit tags="kvdb_postgres")	17m 35s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	3s
run macOS itest	1h 1m 12s
run unit tests (unit tags="kvdb_sqlite")	15m 55s
run unit tests (btcd unit-race)	35m 31s
run unit tests (unit-module)	1m 3s
check release notes updated	6s
run ubuntu itests (btcd, backend=btcd cover=1)	44m 34s
run ubuntu itests (bitcoind, backend=bitcoind cover=1)	51m 36s
run ubuntu itests (bitcoind-notxindex, backend="bitcoind notxindex")	50m 50s
run ubuntu itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling" cover=1)	50m 57s
run ubuntu itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	1h 5m 36s
run ubuntu itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	1h 17m 30s
run ubuntu itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	52m 29s
run ubuntu itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	1h 18m 0s
run ubuntu itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	34m 49s
run ubuntu itests (neutrino, backend=neutrino cover=1)	46m 32s
finish	3s
	13h 22m 47s

Provide feedback