rtspsrc: Fix session cleanup when handling redirect on PLAY

Redirect on PLAY wasn't doing the necessary session cleanup. Fixed by
removing code from gst_rtspsrc_send that changed the state varable upon
encountering a redirect. Better to let the redirect handlers in
gst_rtspsrc_retrieve_sdp and gst_rtspsrc_play do their own
state-dependent cleanup.

https://bugzilla.gnome.org/show_bug.cgi?id=775543

gst/rtsp/gstrtspsrc.c

@@ -5571,7 +5571,6 @@ error_response:
           src->conninfo.url->transports = transports;
 
         src->need_redirect = TRUE;
-        src->state = GST_RTSP_STATE_INIT;
         res = GST_RTSP_OK;
         break;
       }