404 dead links found by Google Webmaster-Tools but not by Broken Link Checker

Hi guys,

I have a problem with internal dead links.
The google Webmaster-Tools tell me, that there are some dead links found while crawling my website. I tried to check that out but could not find them. Even the installed “Broken Link Checker” does not report any bad link.
As I opened the full source code of the relevant site I could finally find the link. But I don’t know how to remove it. Perhaps someone can give me some advise with this. Here is the info:

– dead link (as stated in webmaster-tools): …/comments/feed
– relevant website:
– extract of source code:

<title>Naturheilpraxis Melanie Wagner : Fu?reflexzonenmassage</title>

<!-- BEGIN Metadata added by Add-Meta-Tags WordPress plugin
Get the plugin at: https://www.g-loaded.eu/2006/01/05/add-meta-tags-wordpress-plugin/ -->
<meta name="description" content="Mithilfe der Fu?reflexzonenmassage kann man bestimmte K?rperbereiche sowohl stimulieren und aktivieren als auch sedieren (beruhigen). Da der gesamte menschliche K?rper über Reflexzonen auf den Fü?en abgebildet ist, k?nnen verschiedenste St?rungen des gesamten Organismus mit einer Fu?reflexz..." />
<meta name="google-site-verification" content="Xzxa2xP8rKB_GjIahRNo8goXRFwl0ux70ory82p1JGw" />
<!-- END Metadata added by Add-Meta-Tags WordPress plugin -->

<link rel="alternate" type="application/rss+xml" title="Naturheilpraxis Melanie Wagner ? Feed" href="https://www.naturheilpraxis-melaniewagner.de/feed/" />
<link rel="alternate" type="application/rss+xml" title="Naturheilpraxis Melanie Wagner ? Kommentar-Feed" href="https://www.naturheilpraxis-melaniewagner.de/comments/feed/" />

– full source code: https://pastebin.com/3ubzSsqZ