Ensure that node names are lowerecased before matching

The name field is always lowercase whereas the nodename may not have
been in the past. Ensure that we lowercase it before looking for
matching nodes.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1396350

playbooks/common/openshift-cluster/upgrades/initialize_nodes_to_upgrade.yml

@@ -31,7 +31,7 @@
       with_items: " {{ groups['oo_nodes_to_config'] }}"
       when:
       - hostvars[item].openshift is defined
-      - hostvars[item].openshift.common.hostname in nodes_to_upgrade.results.results[0]['items'] | map(attribute='metadata.name') | list
+      - hostvars[item].openshift.common.hostname | lower in nodes_to_upgrade.results.results[0]['items'] | map(attribute='metadata.name') | list
       changed_when: false
 
   # Build up the oo_nodes_to_upgrade group, use the list filtered by label if