Remove manila-ui undeclared jobs

Manila UI is using some jobs that are no longer declared. Due to
this, zuul is now noticing the usage of a job that is no longer
declared. This change removes the non declared jobs from the stable
branches.

Change-Id: I946f51b4fe0d545190fd741435d4c6521cb2433a

.zuul.yaml

@@ -11,14 +11,10 @@
         - manila-ui-integration-tests:
             voting: false
         - horizon-openstack-tox-python3-django111
-        - horizon-openstack-tox-py27dj19
-        - horizon-openstack-tox-py27dj110
     gate:
       jobs:
         - manila-ui-integration-tests
         - horizon-openstack-tox-python3-django111
-        - horizon-openstack-tox-py27dj19
-        - horizon-openstack-tox-py27dj110
 
 - job:
     name: manila-ui-integration-tests