Using dcommit could cause the user to lose uncommitted changes
during the reset --hard operation, so change it to reset --mixed.
If dcommit chooses the rebase path, then git-rebase will already
error out when local changes are made.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>