Replace view_set_mxid with require_registration

To put all the other flows through the to-ilag-or-not-to-ilag flow

src/components/structures/RoomDirectory.js

@@ -354,7 +354,7 @@ module.exports = React.createClass({
             // to the directory.
             if (MatrixClientPeg.get().isGuest()) {
                 if (!room.world_readable && !room.guest_can_join) {
-                    dis.dispatch({action: 'view_set_mxid'});
+                    dis.dispatch({action: 'require_registration'});
                     return;
                 }
             }