fixed viewer not updating after timeline change

olive.pro.user

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 4.6.2, 2018-06-22T22:15:57. -->
+<!-- Written by QtCreator 4.6.2, 2018-06-23T00:49:14. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>

panels/timeline.cpp

@@ -232,6 +232,7 @@ void Timeline::redraw_all_clips(bool changed) {
         if (changed) {
             project_changed = true;
             if (!playing) reset_all_audio();
+            panel_viewer->viewer_widget->update();
         }
 
         ui->video_area->redraw_clips();