[gtkmm] FileChooserDialog: Use static_cast, not C cast

[Daniel Boles <dboles src gnome org>]

commit f57fa9f9668958a002fc9faaff1812fde54a9bfb
Author: Daniel Boles <dboles src gnome org>
Date:   Mon Mar 27 18:10:28 2017 +0100

    FileChooserDialog: Use static_cast, not C cast
    
    static_cast is better C++ style and safer due to compile-time checking.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780004

 gtk/src/filechooserdialog.ccg |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/src/filechooserdialog.ccg b/gtk/src/filechooserdialog.ccg
index b4746ae..9ea6d86 100644
--- a/gtk/src/filechooserdialog.ccg
+++ b/gtk/src/filechooserdialog.ccg
@@ -24,14 +24,14 @@ namespace Gtk
 
 FileChooserDialog::FileChooserDialog(Gtk::Window& parent, const Glib::ustring& title, FileChooserAction 
action)
 :
-  _CONSTRUCT("title", title.c_str(), "action", (GtkFileChooserAction)action)
+  _CONSTRUCT("title", title.c_str(), "action", static_cast<GtkFileChooserAction>(action))
 {
   set_transient_for(parent);
 }
 
 FileChooserDialog::FileChooserDialog(const Glib::ustring& title, FileChooserAction action)
 :
-  _CONSTRUCT("title", title.c_str(), "action", (GtkFileChooserAction)action)
+  _CONSTRUCT("title", title.c_str(), "action", static_cast<GtkFileChooserAction>(action))
 {
 }