Bug 827844 seems to have been fixed upstream. The link now in the man-page is:
https://git.github.io/htmldocs/git.html Using git version 1:2.17.1-1. It looks like it was fixed by Jonathan: commit f79358279c4b447b1318a922e15705d2a00fc5a2 (origin/jn/preformatted-doc-url) Author: Jonathan Nieder <jrnie...@gmail.com> Date: Wed Jun 22 10:38:25 2016 -0700 doc: git-htmldocs.googlecode.com is no more