Check host is not none in each availability zone

Check that host is not none before trying to parse the services that
are up in each availability zone

Change-Id: I757f35ca2fa84da3441b544280c1c430bf3e8fb8
Closes-Bug: #1297920
(adopted from commit 7f30ab5124618c5b11eebf9c6d69bcfd8a47adc3,
change path from 'dashboards/admin/aggregate' to
'dashboards/admin/info')
Original fix by Santiago Baldassin <santiago.b.baldassin@intel.com>
Merge "Check host is not none in each availability zone" into stable/havana
Merge branch 'stable/havana' of https://github.com/openstack/horizon into stable/havana_routerrules