chore(jquery-form): disable AMD loading for compatibility with DXP

In our previous fork of this module, we have an `if (false)` condition
to prevent the module from calling `define`:

    https://github.com/liferay/liferay-portal/blob/19d993d6e3c0dd6865924bf23f75992f52fc355e/modules/apps/frontend-js/frontend-js-jquery-web/src/main/resources/META-INF/resources/jquery/form.js#L33

That's pretty ugly, and just stripping out the conditional is a still a
pretty minimal edit, so let's go with that instead. Note that if you
look at the DXP version, we wrap the entire function in a wrapper that
just passes in `window.$` as `jQuery`, but that changes the indentation
level of the entire file, so to make a minimal edit here we don't do
that.

After this change, we're basically identical to what is in DXP (compared
that by source-formatting the file, overwriting it with the DXP copy,
and inspecting the changes with `git diff -w`).

Author: wincent

third-party/projects/jquery-form/jquery.form.js

@@ -10,16 +10,9 @@
  */
 /*global ActiveXObject */
 
-// AMD support
 (function (factory) {
     "use strict";
-    if (typeof define === 'function' && define.amd) {
-        // using AMD; register as anon module
-        define(['jquery'], factory);
-    } else {
-        // no AMD; invoke directly
-        factory( (typeof(jQuery) != 'undefined') ? jQuery : window.Zepto );
-    }
+    factory(window.$ || window.Zepto);
 }
 
 (function($) {