Need simply editing of line of code found in our wordpress woocommerce themes head section

Job ID: 33528365

Budget: $30 – $250 USD

We have a Wordpress woocommerce theme installed and in the head section of the site there is

<link rel="stylesheet" id="jquery-ui-css" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css?ver=5.9.3" type="text/css" media="all">

We simply want to change the HTTP to https so we adhere to google regarding SEO and the pages affected will be secure.

Our theme developer says there is a plugin or customization that is overriding the themes calling of this CSS file, but we are unable to find it for editing.
Related categories: PHP JavaScript WordPress CSS jQuery / Prototype