pull --rebase: error on no merge candidate cases
pull --rebase: error on no merge candidate cases

Tweak the error messages printed by die_no_merge_candidates() to take
into account that we may be "rebasing against" rather than "merging
with".

Signed-off-by: Paul Tan <ca5433e1cdd25b4a4001c54525dea593b33edc0c@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git