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/827
Closes-Bug: #2028683
Change-Id: I753486de8644d25201ec7138ec2190f66533a340