mkimage-arch.sh - don't run docker in interactive mode
Don't run docker in interactive mode in the archlinux container build script. Recent versions of Docker error out with "cannot enable tty mode on non tty input" when being run non-interactively (such as in a cron job, Jenkins build, etc.)
Signed-off-by: Jared Biel <jared.biel@bolderthinking.com>