[pitivi] mainwindow: Fix logo in the about window

[Alexandru Băluț <alexbalut src gnome org>]

commit 11f9512f2a19fbef7508c45881a2ad6d5f4fa911
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Sun Sep 23 21:52:51 2018 +0200

    mainwindow: Fix logo in the about window
    
    Should have been part of 13f410797f085c59054a0466d03beaa0a81c9989
    
    Fixes #2242

 pitivi/dialogs/about.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/pitivi/dialogs/about.py b/pitivi/dialogs/about.py
index 3ac29ecf..d6dae3ce 100644
--- a/pitivi/dialogs/about.py
+++ b/pitivi/dialogs/about.py
@@ -98,8 +98,7 @@ class AboutDialog(Gtk.AboutDialog):
         documenters = ["Jean-François Fortin Tam <nekohayo gmail com>", ]
         self.set_documenters(documenters)
         self.set_license_type(Gtk.License.LGPL_2_1)
-        self.set_icon_name("pitivi")
-        self.set_logo_icon_name("pitivi")
+        self.set_logo_icon_name("org.pitivi.Pitivi")
         self.connect("response", self.__about_response_cb)
         self.set_transient_for(app.gui)