Fixed meta element "msapplication-config" not being removed from the HTML

In `tasks/real_favicon.js`, when the `link` and `meta` tags are being removed from the `head` of the HTML files before the new ones are inserted, it looks like the script was removing the meta `msapplication-square*` instead of `msapplication-config` resulting in the original `<meta name="msapplication-config" content="/path/to/some/icons/browserconfig.xml">` not being removed and sometimes being duplicated in the head.

I've updated the tests as well so they pass with the change to `tasks/real_favicon.js`. Thanks for this excellent site and Grunt plugin.