client: raise the backlog limits before pausing
client: raise the backlog limits before pausing

We need to raise the backlog limits before pausing the pipeline or else
the appsink might be blocking in the render method in wait_backlog() and
we would deadlock waiting for paused.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=736322

hsteinhaus/gst-rtsp-server,surround-io/gst-rtsp-server,hsteinhaus/gst-rtsp-server,barisdemiray/gst-rtsp-server,thaytan/gst-rtsp-server,hsteinhaus/gst-rtsp-server,surround-io/gst-rtsp-server,thaytan/gst-rtsp-server,barisdemiray/gst-rtsp-server,barisdemiray/gst-rtsp-server,surround-io/gst-rtsp-server,thaytan/gst-rtsp-server