support tts caching

lib/tasks/say.js

@@ -29,8 +29,8 @@ class TaskSay extends Task {
       }, this.synthesizer);
 
       while (!this.killed && this.loop--) {
-        this.logger.debug(`TaskSay: remaining loops ${this.loop}`);
         if (!filepath) {
+          this.logger.debug('TaskSay:exec - retrieving synthesized audio');
           filepath = await synthAudio(opts);
           cs.trackTmpFile(filepath);
         }