plugin loads backbone & underscore js on frontend regardless of asset option true

[chuckreynolds]

This plugin seems to load core js files on frontend regardless if option Enable Asset Loading Restrictions is true:

• /wp-includes/js/underscore.min.js
• /wp-includes/js/backbone.min.js Also add in:
• /wp-content/plugins/custom-contact-forms/wp-api/wp-api.js

These don't load otherwise by theme or other plugins (tested); I'd assume if they're required they'd only load when assets are loaded via options limitations.