Allow new HA app to be created successfully

update_cluster previously assumed that there was always an initial proxy
gear, and that when adding a new proxy gear, it would always be an
increase from e.g. 1 to 2 or more.

Fix update_cluster so it will work correctly when a brand new app is
created with ha=true, in which case the initial call to update_cluster
will contain 2 proxy entries
Bug 1055475 - Mark require_district = true when zones are required in rpc_find_all_available

Fix application functional test
Merge pull request #4769 from ncdc/new-ha-app-fix-update-cluster

Merged by openshift-bot
Merge pull request #4767 from pravisankar/dev/ravi/bug1055475

Merged by openshift-bot
Merge pull request #4775 from danmcp/master

Merged by openshift-bot
Fixing typos