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/misc/params.js

@@ -17,9 +17,10 @@
 // @params and @defaults
 function parse(params = {}, defaults, allowExtras) {
     if (!allowExtras) {
-        for (let prop in params)
+        for (let prop in params) {
             if (!(prop in defaults))
                 throw new Error(`Unrecognized parameter "${prop}"`);
+        }
     }
 
     let defaultsCopy = Object.assign({}, defaults);