I updated all navigation, RSS, links to images, menu, search, sitemap, everything. Dump of my site didn't contain any 'http' link to the same domain.
nginx was redirecting everything with 301.
I let once website work on http and https and made most links protocol-independent, only site map and search results are forced to https. There was a thread about it on reddit where a few more people said the same.
I slightly recovered from it, got 101 UU yesterday.