When going through the rebase+build loop, the repository state won't
match the exact branch or PR history. This results in the `Building:
XYZSHA` indications being entirely useless. Fix this by at least
including the title line of the commit being built. This will allow a
human to make sense of any size-check failure WRT their view of history.
Signed-off-by: Chris Evich <cevich@redhat.com>