[gtkmm-documentation] Adapt to CalendarDisplayOptions as Calendar::DisplayOptions.

[Murray Cumming <murrayc src gnome org>]

commit 7015d03bea745611f7b2e010e95e086d30fd0f10
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed May 3 10:32:28 2017 +0200

    Adapt to CalendarDisplayOptions as Calendar::DisplayOptions.

 examples/others/calendar/calendar.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/examples/others/calendar/calendar.cc b/examples/others/calendar/calendar.cc
index 3148e41..7ce99f3 100644
--- a/examples/others/calendar/calendar.cc
+++ b/examples/others/calendar/calendar.cc
@@ -102,7 +102,7 @@ void CalendarExample::set_flags()
   }
 
   if (calendar_)
-    calendar_->set_display_options((Gtk::CalendarDisplayOptions)options);
+    calendar_->set_display_options((Gtk::Calendar::DisplayOptions)options);
 }
 
 void CalendarExample::toggle_flag(Gtk::CheckButton *toggle)