Remove unused import
Remove the use of the "auto connect retry" option

This option is deprecated without replacement, and doesn't really make sense: if connecting fails before
the connect timeout then it likely won't get fixed by retrying: it must be something other than just time that
prevents us from connecting.

Additionally: the connectTimeout of 15s is exactly the same time that Mongo would automatically retry (see
DBPort#CONN_RETRY_TIME_MS, which is used when #maxAutoConnectRetryTime is not configured), so the retry would never
help.
Use a separate logger for the Monitor thread

The Indexer also uses a separate logger, the Slurper on the other hand uses the global logger.