[pitivi] timeline: Do not reset playhead on button release event on the layer control

[Thibault Saunier <tsaunier src gnome org>]

commit a75353dfca2c33afe5c0fec7880f5fe50e38d1a3
Author: Suhas Nayak <suhas2go gmail com>
Date:   Fri Feb 23 05:49:38 2018 +0530

    timeline: Do not reset playhead on button release event on
    the layer control

 pitivi/timeline/timeline.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 2096f989..47ad09cc 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -739,7 +739,9 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
                 self._project.pipeline.simple_seek(self.__next_seek_position)
                 self.__next_seek_position = None
             else:
-                self._seek(event)
+                event_widget = Gtk.get_event_widget(event)
+                if self._getParentOfType(event_widget, LayerControls) is None:
+                    self._seek(event)
 
         self._snapEndedCb()
         self.update_visible_overlays()