Fix verify_database on centos7 and redhat

On centos7 and redhat, contrail-database is still a SYSV service and
hence its status needs to be checked by looking at the return code of
service contrail-database status rather than the output since the output
does not contain the word running. Pipe-ing head -n 10 changes the return
code to always return 0. The above was broken due to commit for bug #1638670
commit f378fac which made setup_all work
on xenial. Revert the change to verify_service made in that commit.

Change-Id: If38f781713145d28f8725634685f8f98661bc056
Closes-Bug: #1657934

fabfile/tasks/verify.py

@@ -13,7 +13,7 @@ class OpenStackSetupError(Exception):
 def verify_service(service, initd_service=False):
     for x in xrange(10):
         with settings(warn_only=True):
-            output = sudo("service %s status | head -10" % service)
+            output = sudo("service %s status" % service)
         if initd_service:
             if output.succeeded or re.search('Active:.*active', output):
                 return