[cheese] Replace deprecated functions

[David King <davidk src gnome org>]

commit 0b1b07980f621184dfa6c11a8eab25badd72cdf1
Author: esoleyman <emil soleyman com>
Date:   Fri May 24 15:27:47 2019 -0500

    Replace deprecated functions
    
    The thumbnail menu popup functions were updated to match GTK
    
    https://gitlab.gnome.org/GNOME/cheese/issues/9

 src/cheese-window.vala | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)
---
diff --git a/src/cheese-window.vala b/src/cheese-window.vala
index 25df09e7..ff069808 100644
--- a/src/cheese-window.vala
+++ b/src/cheese-window.vala
@@ -149,16 +149,14 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
         return false;
     }
 
-    private void do_thumb_view_popup_menu (Gtk.Widget widget,
-                                           uint button,
-                                           uint time)
+    private void do_thumb_view_popup_menu ()
     {
-        thumbnail_popup.popup (null, widget, null, button, time);
+        thumbnail_popup.popup_at_pointer (null);
     }
 
-    private bool on_thumb_view_popup_menu (Gtk.Widget thumbview)
+    private bool on_thumb_view_popup_menu ()
     {
-        do_thumb_view_popup_menu (thumbview, 0, 0);
+        do_thumb_view_popup_menu ();
 
         return true;
     }
@@ -195,8 +193,7 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
 
             if (button_press->triggers_context_menu ())
             {
-                do_thumb_view_popup_menu (thumb_view, event.button,
-                                          event.time);
+                do_thumb_view_popup_menu ();
                 return true;
             }
         }