l2md: bump open file limit for repos with lots of pack files

Bump the limit to avoid bailing out in git_revwalk_next() without
having walked any commits. This happens when the repo has a lot of
pack files where we otherwise surpass the open file limit with the

Ideally doing an equivalent of ...

  git repack -a -d -f --depth=250 --window=250

... out of libgit2 would be best and solve this issue, but given
GH issue [0], it's not there yet (if ever).

  [0] https://github.com/libgit2/libgit2/issues/3247

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1 file changed