WP Website Not Working after Using Defender

Hi,

After I clicked the Auto-patch function of Defender, it deleted a file in my WP core. Now my website is not accessible. Please help to undo!

These are the changes made as seen in email from Defender.

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Hi chemactiv,

WP Defender here, reporting back from the front.

I've finished scanning http://chemactiv.com for vulnerabilities and I found 2 issues that you should take a closer look at!

File Issue
upgrade.php
/wp-admin/includes/upgrade.php This WordPress core file appears modified
gd-config.php
/gd-config.php Unknown file in WordPress core
Follow me back to the lair and let's get you patched
up.

Stay Safe,
WP Defender
Official WPMU DEV Superhero