Updated git submodules

Updated git submodules

Project: releng/builder master 1682cc57ffcd4287ddeb0f86da65607eeca41188

Wait for DNS before attempting git clone

Sometimes cloud-init comes online but DNS is not yet available when our
user-data script runs (see error example below). Let's loop infinitely
until git.opendaylight.org is resolvable.

Feb 18 01:45:02 centos-7---devstack-mitaka---20170210-1356 cloud-init:
fatal: unable to access 'https://git.opendaylight.org/gerrit/releng/builder/':
  Could not resolve host: git.opendaylight.org; Unknown error

Trello: https://trello.com/c/grIk0LdG
Change-Id: I038af66b0bce9142f0da7d26b4f26959914ae6b2
Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>