repo_synchroniser: avoid non fast-forward and nothing changed issues (bug 1965991)#49

shtrom wants to merge 10 commits into

mainmozilla-conduit/git-hg-sync:mainfrom

bug1963805/noop-on-ancestor-commitmozilla-conduit/git-hg-sync:bug1963805/noop-on-ancestor-commitCopy head branch name to clipboard