Fix ups for 6525ccc384ca8ae6fe4f3fda6b7bb57156691706

If log_path is empty, we shouldn't setChatLogsDir to it.
In fact, this may have been the cause of something Nomade Zhao brought up.

Also, InstantMessageLogPathAnyAccount was accidentally being set as a PerAccount
Merge remote-tracking branch 'lirusaito/master'