error event handler is never removed

When reinitializing, an 'error' event handler is added to the old client, which is not later removed:

Line 266 in fcafcab

    
           dbClient.once("error", error => connectionLogger(`Previous DB client errored after reconnecting already:`, error))

Perhaps an idea to wait for the client to end and then remove the listeners again?

await dbClient.end();
dbClient.removeAllListeners();