Merge branch '2.0release' into develop

@@ -477,7 +477,6 @@ vhost http.remux.srs.com {
         # whether http stream trigger rtmp stream source when no stream available,
         # for example, when encoder has not publish stream yet,
         # user can play the http flv stream and wait for stream.
-        # TODO: FIXME: for edge vhost, automatically trigger the backsource connection.
         # default: on
         hstrs       on;
     }