[gnome-boxes/vala-fix-3.34] app-window: Fix build with vala master

[Felipe Borges <felipeborges src gnome org>]

commit 8aaf59870b9972f228e073a674b254b1e4cda2de
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Mon Oct 28 10:36:20 2019 -0500

    app-window: Fix build with vala master
    
    Cherry-picked from a1522749a9651915132fc1171d31a1c22df423ab
    
    See #431

 src/app-window.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/app-window.vala b/src/app-window.vala
index 8a1ebb6a..82a9f834 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -438,7 +438,7 @@ public bool on_key_pressed (Widget widget, Gdk.EventKey event) {
 
             return true;
         } else if (event.keyval == Gdk.Key.A &&
-                   (event.state & default_modifiers) == Gdk.ModifierType.CONTROL_MASK | 
Gdk.ModifierType.SHIFT_MASK) {
+                   (event.state & default_modifiers) == (Gdk.ModifierType.CONTROL_MASK | 
Gdk.ModifierType.SHIFT_MASK)) {
             foreach_view ((view) => { view.unselect_all (); });
 
             return true;