media: media has to be unprepared in finalize
media: media has to be unprepared in finalize

Because unprepare takes away the last ref on the media.

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