cleanup: Use consistent brace style of blocks

Our coding style has always been to either put braces around all
blocks, or avoid them for all. Fix the couple of places that slipped
through.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/731

js/extensionPrefs/main.js

@@ -285,8 +285,9 @@ var Application = GObject.registerClass({
                     log(`Failed to connect to shell proxy: ${e}`);
                     this._mainStack.add_named(new NoShellPlaceholder(), 'noshell');
                     this._mainStack.visible_child_name = 'noshell';
-                } else
+                } else {
                     throw e;
+                }
                 return;
             }