[gnome-sound-recorder] play.js: Get rid of error message for null waveform

[Meg Ford (Margaret) <megford src gnome org>]

commit ee8ba599c954d21863d30ef45499b58743328610
Author: Meg Ford <megford gnome org>
Date:   Mon May 5 14:19:24 2014 -0500

    play.js: Get rid of error message for null waveform

 src/play.js |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/src/play.js b/src/play.js
index 564f49f..f1289d3 100644
--- a/src/play.js
+++ b/src/play.js
@@ -190,7 +190,10 @@ const _TENTH_SEC = 100000000;
  
         this.runTime = absoluteTime- this.baseTime;
         let approxTime = Math.round(this.runTime/_TENTH_SEC);
-        MainWindow.wave._drawEvent(approxTime);
+        
+        if (MainWindow.wave != null) {
+            MainWindow.wave._drawEvent(approxTime);
+        }
         
         return true;
     },