services: only read from TTS websocket if websocket connection established

src/pipecat/services/fish/tts.py

@@ -104,7 +104,8 @@ class FishAudioTTSService(InterruptibleTTSService):
 
     async def _connect(self):
         await self._connect_websocket()
-        if not self._receive_task:
+
+        if self._websocket and not self._receive_task:
             self._receive_task = self.create_task(self._receive_task_handler(self._report_error))
 
     async def _disconnect(self):