libgit2/objective-git — pull request #385 by itmm (2014-07-15 18:40:01+00:00)
Title: if you want to ignore errors, you need to pass 0

It didn't work for me to ignore the certificates (due to the problems on iOS with github). But I guess, the semantic is flipped: git_remote_check_cert expects a flag, wether to check for a cert, not if to ignore the check.