Don't lock a global table if the chain to be searched is empty #2447

Job	Run time
JE (FreeBSD arm64)	49m 32s
JE (FreeBSD vmactions)	0s
JE (FreeBSD cross-platform-actions)	16m 46s
JE (android)	23m 51s
JE (Linux)	14m 45s
JE (Linux gcc)	17m 46s
JE (macOS)	25m 4s
JE (macOS arm64)	18m 13s
JE (OpenBSD vmactions)	0s
JE (OpenBSD cross-platform-actions)	16m 13s
JE (OpenBSD arm64)	39m 24s
JE (Raspberry32)	16m 42s
JE (Raspberry)	41m 8s
JE (wasm)	1m 42s
JE (Windows)	25m 39s
JE (Windows 32)	3m 10s
JE (Windows arm64)	6m 46s
Test Results	0s
Run Webhook	0s
	5h 16m 41s

Provide feedback