Reset peer timer after logon

[bhaan]

We were seeing a test request (35=1) being sent immediately after logon for our acceptor. After looking into this, it appears that the peerTimer was being reset before having processed the logon request form the initiator. Because the initiator's logon contains the heartbeat interval, the acceptor was trying to reset the timer with a zero value, ultimately causing the peer timer to activate immediately.

The following changes will prevent timers from being reset with a zero value, and ensures that the timer is reset once the logon (and heartbeat interval) is received.