mpegtsdemux: Fix sticky event handling

When we receive sticky events from upstream, always return TRUE.

Fixes the issue where we receive custom sticky events (such as "uri")
and no pads are created yet.

gst/mpegtsdemux/mpegtsbase.c

@@ -1095,6 +1095,10 @@ mpegts_base_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
       res = GST_MPEGTS_BASE_GET_CLASS (base)->push_event (base, event);
   }
 
+  /* Always return TRUE for sticky events */
+  if (GST_EVENT_IS_STICKY (event))
+    res = TRUE;
+
   return res;
 }