Remove message from inflight when not connected

Remove message from inflight when not connected

Publishes with qos > 0 which are sent before a CONACK is received are still counted as inflight
even though they don't really get sent.  This means they get sent after the retry period (20 sec default)

But this won't work when max_inflight is 1 since this means no retry will get sent and we wait untill keepalive is exhausted
This then forces a reconnect and will reset stuff so messages can be sent.

Change-Id: I516a6cce8e5bbfbd3030711a80044af4e5bf6733
Signed-off-by: Hmvp <hmvp@hmvp.nl>