ubuntu template: set -e to return error on failures.
ubuntu template: set -e to return error on failures.

Otherwise callers can get bad containers without knowing it.

Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/922645

Signed-off-by: Serge Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>

ostap/lxc,ostap/lxc