WIP: rtspconnection: Only reset timeout when socket is unused
After sending or retrieving data, gstrtspconnection resets the socket's timeout to 0 (infinite). This could cause problems when different threads use the same socket simultaneously. For example, if RTCP data is sent from the streaming thread while gstrtspsrc is already retrieving data.
With this patch, timeout is only reset to 0 if there is no other threads using the socket.
(currently WIP as patch is also being reviewed locally)