`bitcoin-cli loadwallet "wallet.dat"` command causes bitcoind crash

log info:
```
bitcoind: wallet/db.cpp:236: BerkeleyEnvironment::VerifyResult BerkeleyEnvironment::Verify(const string&, BerkeleyEnvironment::recoverFunc_type, std::__cxx11::string&): Assertion `mapFileUseCount.count(strFile) == 0' failed.
Aborted (core dumped)
```

Bitcoin Core Daemon version `v0.17.0.0-ge1ed37edaedc85b8c3468bd9a726046344036243`

LOCK(cs_db);
            if (!env->mapFileUseCount.count(strFile) || env->mapFileUseCount[strFile] == 0)
            {
                
                env->CloseDb(strFile);
                env->CheckpointLSN(strFile);
                env->mapFileUseCount.erase(strFile);
                
                fs::path pathSrc = env->Directory() / strFile;
                fs::path pathDest(strDest);
                if (fs::is_directory(pathDest))
                    pathDest /= strFile;
                try {
                    if (fs::equivalent(pathSrc, pathDest)) {
                        LogPrintf("cannot backup to wallet source file %s\n", pathDest.string());
                        return false;
                    }
                    fs::copy_file(pathSrc, pathDest, fs::copy_option::overwrite_if_exists);
                    LogPrintf("copied %s to %s\n", strFile, pathDest.string());
                    return true;
                } catch (const fs::filesystem_error& e) {
                    LogPrintf("error copying %s to %s - %s\n", strFile, pathDest.string(), fsbridge::get_filesystem_error_message(e));
                    return false;
                }
            }
        }
        MilliSleep(100);
    }
}
void BerkeleyDatabase::Flush(bool shutdown)