Handle logon error

[zee276]

PR handles the logon error which can be observed when database is down for some period of time.

Way to reproduce that issue is to start fix initiator with sql database as store. Then stop database for a period of time and start it back up. This results in the following 2 issues:

• initiator stops its retrying logic as the logon error is ignored
• CPU usage is significantly increasing since session fails to transition to disconnected state and it constantly reads from a closed channel. It reads this closed channel here and the handling of that closed channel here is not working since it tries to transition the session to disconnected but we are already disconnected so that is a noop.

PR fixes it by handling the logon errors accordingly.