Connection multiplexing: Closing all sessions to an IP address on CIP connection timeouts is too hard

When a Class3 or Class1 connection times out, then the connection manager calls into the encap layer, requesting it to close all sessions to the peer's IP address. Of course, a single host can have multiple connection towards our device, which all would get closed in that situation. Not exactly what we want.

Just lookup the underlying transport for each timed out connection and close that particular transport only.