[gnome-games] application-window: Explicitly null-check application after cast

[Alexander Mikhaylenko <alexm src gnome org>]

commit a2405f6b696dde39e687c2db0533678bd4f2e35a
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Oct 10 02:23:45 2019 +0500

    application-window: Explicitly null-check application after cast
    
    Apparently, `is Application` is not enough anymore, so try to cast and
    null-check instead to avoid a compile-time warning.

 src/ui/application-window.vala | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/src/ui/application-window.vala b/src/ui/application-window.vala
index 4965b963..ae12abc8 100644
--- a/src/ui/application-window.vala
+++ b/src/ui/application-window.vala
@@ -22,8 +22,10 @@ private class Games.ApplicationWindow : Gtk.ApplicationWindow {
                        if (current_view != null)
                                current_view.is_view_active = true;
 
-                       assert (application is Application);
-                       (application as Application).set_pause_loading (current_view != collection_view);
+                       var app = application as Application;
+                       assert (app != null);
+
+                       app.set_pause_loading (current_view != collection_view);
                }
        }