[gtkmm] Label: improve h/valign constructor doc comment

[Murray Cumming <murrayc src gnome org>]

commit 43b1945accd2077f5b5b18dcff66dae33407496e
Author: djb <db0451 gmail com>
Date:   Thu Nov 17 22:21:47 2016 +0000

    Label: improve h/valign constructor doc comment
    
    https://bugzilla.gnome.org/show_bug.cgi?id=774652

 gtk/src/label.hg |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/gtk/src/label.hg b/gtk/src/label.hg
index 6f09f86..bbe752e 100644
--- a/gtk/src/label.hg
+++ b/gtk/src/label.hg
@@ -43,9 +43,8 @@ public:
   Label();
   explicit Label(const Glib::ustring& label, bool mnemonic = false);
 
-  /** This constructor is a shortcut for often used code
-   * when you want to create a label with alignment different
-   * than default one.
+  /** This constructor is a shortcut to create a Label with Widget
+   * alignment properties different from the default ALIGN_FILL.
    * @code
    * Gtk::Label label(text, h, v, mnemonic);
    * @endcode