[meld] filediff: Fix deprecated constructor call

[Kai Willadsen <kaiw src gnome org>]

commit e113e92eed7580e4a55a4020926b32c4a273e46a
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Dec 21 11:58:38 2014 +1000

    filediff: Fix deprecated constructor call

 meld/filediff.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index e85d80a..e8b33da 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -855,7 +855,7 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
             # but this is unbound on currently required PyGTK.
             buttons = []
             for i in range(self.num_panes):
-                button = Gtk.CheckButton(self.textbuffer[i].data.label)
+                button = Gtk.CheckButton(label=self.textbuffer[i].data.label)
                 button.set_use_underline(False)
                 button.set_sensitive(modified[i])
                 button.set_active(modified[i])