Increase height of default window, per follow-on to http://bugzilla.audacityteam.org/show_bug.cgi?id=547#c10.

Restore a comment.

src/effects/TruncSilence.cpp

@@ -582,6 +582,7 @@ bool EffectTruncSilence::Process()
 
       delete [] buffer;
 
+      // Buffer has been freed, so we're OK to return if cancelled
       if (cancelled) 
       {
          ReplaceProcessedTracks(false);