[gtkmm] Tiny whitespace change.

[Murray Cumming <murrayc src gnome org>]

commit 6210894077a2013ccb9c38f53cd7238240c2e403
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Aug 5 09:39:29 2016 +0200

    Tiny whitespace change.

 gtk/src/shortcutlabel.hg |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gtk/src/shortcutlabel.hg b/gtk/src/shortcutlabel.hg
index 8ffb611..f28e268 100644
--- a/gtk/src/shortcutlabel.hg
+++ b/gtk/src/shortcutlabel.hg
@@ -38,6 +38,7 @@ class ShortcutLabel : public Box
 
 public:
   _CTOR_DEFAULT
+
   /** Creates a %ShortcutLabel with accelerator set.
    *
    * @param accelerator The initial accelerator.