fix #1466: (#1467)

* fix #1466:

* do not send tts streaming events when we are not doing tts streaming

lib/tasks/gather.js

@@ -881,7 +881,7 @@ class TaskGather extends SttTask {
         this._fillerNoiseOn = false;  // in a race, if we just started audio it may sneak through here
         this.ep.api('uuid_break', this.ep.uuid)
           .catch((err) => this.logger.info(err, 'Error killing audio'));
-        cs.clearTtsStream();
+        if (cs.isTtsStreamEnabled) cs.clearTtsStream();
       }
       return;
     }