Fix octavia ca/cert generation

In current implementation salt.minion state fails with
"Detected conflicting IDs, SLS IDs need to be globally unique.
The conflicting ID is '/etc/octavia/certs/ca_01.pem' and is found
in SLS 'base:salt.minion.ca' and SLS 'base:salt.minion.cert'"

Need to delete ca_file and ca_key_file params to fix the above
problem, so minion.cert will create them by itself.

Change-Id: I62beb12becb2d07bdd10d44ee44814eab9e03b07
1 file changed