fix issue in prev commit for microsoft

lib/synth-audio.js

@@ -170,8 +170,6 @@ async function synthAudio(client, logger, stats, { account_sid,
 
     client.setexAsync(key, EXPIRES, audioBuffer.toString('base64'))
       .catch((err) => logger.error(err, `error calling setex on key ${key}`));
-
-    if (['microsoft'].includes(vendor)) return {filePath, servedFromCache, rtt};
   }
 
   return new Promise((resolve, reject) => {
@@ -325,9 +323,9 @@ const synthMicrosoft = async(logger, {
               reject(cancellation.errorDetails);
               break;
             case ResultReason.SynthesizingAudioCompleted:
-              stats.increment('tts.count', ['vendor:microsoft', 'accepted:yes']);
               resolve(Buffer.from(result.audioData));
               synthesizer.close();
+              stats.increment('tts.count', ['vendor:microsoft', 'accepted:yes']);
               break;
             default:
               logger.info({result}, 'synthAudio: (Microsoft) unexpected result');