stable/12 git -> svn mirror delayed

[Ed Maste]

The git-svn stable/12 mirror is currently stuck. It encountered an
issue with the OpenSSL 1.1.1j import (e3a8c0df593b) and hasn't been
able to make progress past it. It's under investigation and will
hopefully be resolved soon.

(I think the git-svn converter is trying to cherry-pick each of the
vendor updates on the branch 4f55bd5321b7 rather than a single commit
for the merge itself.)