When SERVICE_HOST is defined to literal IPv6 address
(i.e., [fdf8:f53b:82e4::179]) we will have to include
--globoff option for curl to be able to reach the various
openstack services. Using globoff works for both IPv6 and
IPv4 urls, so its safe to include this option for all curl
statements in devstack.
Closes-Bug: #1424943
Change-Id: I2afc16f2f94d7d7069b0ba61bc8348c03413e4e7