fix(xmpp/Caps): features for a user without caps support

If there's no capabilities version mapping to user's jid
still allow to discover features (that's the case for Jicofo).

modules/xmpp/Caps.js

@@ -171,6 +171,8 @@ export default class Caps extends Listenable {
 
                         return Promise.reject(ERROR_FEATURE_VERSION_MISMATCH);
                     }
+
+                    return features;
                 });
         }