cleanup: Only omit braces for single-line blocks

Braces can be avoided when a block consists of a single statement,
but readability suffers when the statement spans more than a single
line.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/805

js/ui/backgroundMenu.js

@@ -36,10 +36,11 @@ function addBackgroundMenu(actor, layoutManager) {
 
     let clickAction = new Clutter.ClickAction();
     clickAction.connect('long-press', (action, theActor, state) => {
-        if (state == Clutter.LongPressState.QUERY)
+        if (state == Clutter.LongPressState.QUERY) {
             return ((action.get_button() == 0 ||
                      action.get_button() == 1) &&
                     !actor._backgroundMenu.isOpen);
+        }
         if (state == Clutter.LongPressState.ACTIVATE) {
             let [x, y] = action.get_coords();
             openMenu(x, y);