fixing the duration function so that it wont break the javascript if metadata is not defined

common/lib/xmodule/xmodule/js/src/video/01_initialize.js

@@ -779,12 +779,17 @@ function (VideoPlayer, VideoStorage, i18n) {
 
     function getDuration() {
         try {
-            return moment.duration(this.metadata[this.youtubeId()].duration, moment.ISO_8601).asSeconds();
+           return moment.duration(this.metadata[this.youtubeId()].duration, moment.ISO_8601).asSeconds();
         } catch (err) {
-            return _.result(this.metadata[this.youtubeId('1.0')], 'duration') || 0;
+            try{
+                return _.result(this.metadata[this.youtubeId('1.0')], 'duration');
+            } catch (err) {
+                return  0;
+            } 
         }
     }
 
+
     /**
      * Sets player mode.
      *