Clients must be identified with all key attributes instead of only the identifier

[gitseti]

Input:
hmq> con -i myClient -h mybroker.com -p 1884 -v 3
hmq> pub -i myClient -t test -m msg

Expected:
The publish command uses the previously connected client which is uniquely identified with "myClient".

Result:
Publish connects a new client to default settings.

Reason:
The client lookup in the client cache uses a key consisting of mqtt-version, host, port and identifier instead of using solely the identifier.