Merge branch 'jk/committer-date-is-author-date-fix'

In 2.29, "--committer-date-is-author-date" option of "rebase" and
"am" subcommands lost the e-mail address by mistake, which has been
corrected.

* jk/committer-date-is-author-date-fix:
  rebase: fix broken email with --committer-date-is-author-date
  am: fix broken email with --committer-date-is-author-date
  t3436: check --committer-date-is-author-date result more carefully

diff --cc builtin/am.c
Simple merge

diff --cc sequencer.c
Simple merge