fix(checkbox): prevent readonly toggle via space

Prevent a checkbox change via tab+space when it is declared as readonly

Author: lubber-de

src/definitions/modules/checkbox.js

@@ -241,7 +241,9 @@
                             $input.trigger('blur');
                             shortcutPressed = true;
                             event.stopPropagation();
-                        } else if (!event.ctrlKey && module.can.change()) {
+                        } else if (!module.can.change()) {
+                            shortcutPressed = true;
+                        } else if (!event.ctrlKey) {
                             if (key === keyCode.space || (key === keyCode.enter && settings.enableEnterKey)) {
                                 module.verbose('Enter/space key pressed, toggling checkbox');
                                 module.toggle();