rtpptdemux: Remove pads also in PAUSED->READY

They're based on per-stream information and that should be reset
whenever going to READY state.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/1018>

gst/rtpmanager/gstrtpptdemux.c

@@ -744,8 +744,8 @@ gst_rtp_pt_demux_change_state (GstElement * element, GstStateChange transition)
 
   switch (transition) {
     case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
-    case GST_STATE_CHANGE_PAUSED_TO_READY:
       break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
     case GST_STATE_CHANGE_READY_TO_NULL:
       gst_rtp_pt_demux_release (ptdemux);
       break;