[gnome-tweak-tool] about: Mention Tweak Tool version

[Jeremy Bicha <jbicha src gnome org>]

commit 5543a2bbd43aa68db4ac60cb689276a489151545
Author: Jeremy Bicha <jbicha ubuntu com>
Date:   Sun May 28 15:11:03 2017 -0400

    about: Mention Tweak Tool version
    
    https://bugzilla.gnome.org/show_bug.cgi?id=783149

 gtweak/app.py |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtweak/app.py b/gtweak/app.py
index 288af98..7e4ecc5 100644
--- a/gtweak/app.py
+++ b/gtweak/app.py
@@ -22,6 +22,7 @@ from gi.repository import Gio
 from gi.repository import GLib
 
 import gtweak 
+from gtweak.defs import VERSION
 from gtweak.tweakmodel import TweakModel
 from gtweak.tweakview import Window
 from gtweak.utils import SchemaList
@@ -92,6 +93,7 @@ class GnomeTweakTool(Gtk.Application):
 
     def about_cb(self, action, parameter):
         aboutdialog = Gtk.AboutDialog(modal=True, transient_for=self.win)
+        aboutdialog.set_program_name(aboutdialog.get_program_name() + " %s" % VERSION)
 
         _shell = GnomeShellFactory().get_shell()
         if _shell is not None: