rtsp-stream: fixed segmenation fault in _get_server_port()
Calling function gst_rtsp_stream_get_server_port() results in segmenation fault in the RTP/RTSP/TCP case. Port that the server will use to receive RTCP makes only sense in the UDP case, however the function should handle the TCP case in a nicer way. https://bugzilla.gnome.org/show_bug.cgi?id=776345