git/githistory/log: make Close() a no-op for nil receiver
git/githistory/log: make Close() a no-op for nil receiver

aleb/git-lfs,github/git-lfs,dakotahawkins/git-lfs,github/git-lfs,aleb/git-lfs,Jericho25/-git-lfs_miilkyway,aleb/git-lfs,github/git-lfs,Jericho25/-git-lfs_miilkyway,Jericho25/-git-lfs_miilkyway,dakotahawkins/git-lfs,dakotahawkins/git-lfs