Handle state change failures better
Handle state change failures better

Handle state change failures better when changing the state of the pipeline to
determine the SDP.

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