Check host is not none in host aggregate page

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
(cherry picked from commit 7f30ab5124618c5b11eebf9c6d69bcfd8a47adc3)
Merge "Check host is not none in host aggregate page" into stable/icehouse