chainntnfs: fix `TestHistoricalConfDetailsTxIndex` #16751

Job	Run time
check commits	12m 41s
lint code	7m 50s
cross compilation	31m 44s
RPC and mobile compilation check	7m 2s
check pinned dependencies (google.golang.org/grpc v1.59.0)	4s
sample configuration check	5m 0s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	5s
Sqlc check	5m 0s
run unit tests (btcd unit-cover)	20m 9s
run unit tests (unit tags="kvdb_etcd")	21m 25s
run macOS itest	52m 59s
run unit tests (unit tags="kvdb_postgres")	20m 9s
run ubuntu itests (btcd, backend=btcd cover=1)	35m 34s
run unit tests (unit tags="kvdb_sqlite")	18m 45s
run ubuntu itests (bitcoind, backend=bitcoind cover=1)	41m 1s
run windows itest	6m 29s
run unit tests (btcd unit-race)	39m 59s
run ubuntu itests (bitcoind-notxindex, backend="bitcoind notxindex")	40m 42s
run unit tests (unit-module)	5m 11s
run ubuntu itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling" cover=1)	42m 59s
check release notes updated	0s
run ubuntu itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	51m 2s
run ubuntu itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	1h 12m 4s
run ubuntu itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	43m 8s
run ubuntu itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	1h 11m 50s
run ubuntu itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	42m 16s
run ubuntu itests (neutrino, backend=neutrino cover=1)	39m 49s
finish	5s
	12h 15m 2s

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