This is a rebuild/make sync for charms to pickup the fix in charmhelpers to fix
any inadvertant accesses of ['ca'] in the relation data before it is available
from vault in the certificates relation. Fix in charmhelpers is in [1].
[1] https://github.com/juju/charm-helpers/pull/831
Closes-Bug: #2028683
Change-Id: I650b08874523be8b05abffedb7a630b98068d08e