[gnome-calendar] month-popover: Properly mark static function as static

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit a8d6bfea0bf25438ef5e9cda510fe08fa5954668
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sat Jan 27 14:30:31 2018 -0200

    month-popover: Properly mark static function as static

 src/views/gcal-month-popover.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/views/gcal-month-popover.c b/src/views/gcal-month-popover.c
index fe9e53b5..042af573 100644
--- a/src/views/gcal-month-popover.c
+++ b/src/views/gcal-month-popover.c
@@ -163,7 +163,7 @@ animate_size (GcalMonthPopover *self,
   dzl_set_weak_pointer (&self->size_animation, animation);
 }
 
-void
+static void
 update_maximum_height (GcalMonthPopover *self)
 {
   GdkWindow *window;