[pitivi] medialibrary: Remove default value for argument which is always passed

[Alexandru Băluț <alexbalut src gnome org>]

commit 2a2b6171a73cf45b6fe805934f31fb1d92ec0977
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Mon Jun 27 19:39:12 2016 +0200

    medialibrary: Remove default value for argument which is always passed
    
    Differential Revision: https://phabricator.freedesktop.org/D1140

 pitivi/medialibrary.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/medialibrary.py b/pitivi/medialibrary.py
index 00cf5f9..0d1cc94 100644
--- a/pitivi/medialibrary.py
+++ b/pitivi/medialibrary.py
@@ -1087,7 +1087,7 @@ class MediaLibraryWidget(Gtk.Box, Loggable):
             self.app.gui.showProjectSettingsDialog()
         infobar.hide()
 
-    def _clipPropertiesCb(self, unused_widget=None):
+    def _clipPropertiesCb(self, unused_widget):
         """Shows the clip properties in a dialog.
 
         Allows selecting and applying them as the new project settings.