[BUG] Bifrost spit out a lot `fail to remove signed transaction hash` error

{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:09Z","message":"fail to remove signed transaction hash: 0x95670f7caaffebf283d99cc3aef53790cb9ea5123558368ce889df43aa958550"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:09Z","message":"fail to remove signed transaction hash: 0x9d26f9218041fa53a2d36da1984f90af54dd59aef6173998277ae75458862af8"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:09Z","message":"fail to remove signed transaction hash: 0xabc90cf8df7ac7a0b48c9785236f4212f3c50f0aab8065c273bbe11710e331d8"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:09Z","message":"fail to remove signed transaction hash: 0x7632ad8e33eda1395024697447cd4db264bd1061026036139ba498bd599fb675"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:09Z","message":"fail to remove signed transaction hash: 0x87589826f4c3e85b946a19a09193ce588fbae28c438a71ec37a071c62827865f"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:10Z","message":"fail to remove signed transaction hash: 0x3ace713f95fef5c80406f7db7c55cd09267be683eded5ffed6128737d1295f07"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:10Z","message":"fail to remove signed transaction hash: 0x189275198e3aacf8bb3ff20da946ca70d1e84ecbfcf368e2f34a493068aa7329"}
{"level":"error","service":"bifrost","module":"SignerCacheManager","error":"leveldb: not found","time":"2021-11-29T04:56:10Z","message":"fail to remove signed transaction hash: 0x36ab89f40cd2260d3085a10664eb42086dcab0464239229c3bc482c524629a94"}

Bifrost spit out a lot error , which is harmless , but annoying