Merge branch 'sc/sequencer-gpg-octopus'

"git rebase --rebase-merges" did not correctly pass --gpg-sign command line option to underlying "git merge" when replaying a merge using non-default merge strategy or when replaying an octopus merge (because replaying a two-head merge with the default strategy was done in a separate codepath, the problem did not trigger for most users), which has been corrected. * sc/sequencer-gpg-octopus: t3435: add tests for rebase -r GPG signing sequencer: pass explicit --no-gpg-sign to merge sequencer: fix gpg option passed to merge subcommand