fix #1466: (#1467)

* fix #1466:

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

lib/utils/stt-latency-calculator.js

@@ -127,7 +127,6 @@ class SttLatencyCalculator extends Emitter {
 
   calculateLatency() {
     if (!this.isRunning) {
-      this.logger.debug('Latency calculator is not running, cannot calculate latency, returning default values');
       return null;
     }