[iagno] Add Ctrl-q shortcut for quitting.

[Arnaud B. <arnaudb src gnome org>]

commit f300a4c0d60726b9cfe27f9d7c3bd09d4bbe01d8
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Jan 7 18:32:05 2019 +0100

    Add Ctrl-q shortcut for quitting.

 src/iagno.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/iagno.vala b/src/iagno.vala
index 9ec80fb..5ddfe0a 100644
--- a/src/iagno.vala
+++ b/src/iagno.vala
@@ -191,6 +191,7 @@ public class Iagno : Gtk.Application
         add_action_entries (app_actions, this);
         set_accels_for_action ("win.new-game",          {        "<Primary>n"       });
         set_accels_for_action ("win.start-game",        { "<Shift><Primary>n"       });
+        set_accels_for_action ("app.quit",              {        "<Primary>q"       });
         set_accels_for_action ("win.undo",              {        "<Primary>z"       });
         set_accels_for_action ("win.redo",              { "<Shift><Primary>z"       });
         set_accels_for_action ("win.back",              {                 "Escape"  });