Prevents protocol incoming data read from stopping when handling large requests.

Keeps reading available data from the socket even if not a entire line is available,
this way readyRead signals will be emitted when new data arrives in the socket.

Change-Id: Id8b2eab5cf427dd6db3f8f434515964d4c7dbe4f
Reviewed-by: Matthew Vogt <matthew.vogt@qinetic.com.au>