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
diff --git a/salt/minion/ca/octavia_ca.yml b/salt/minion/ca/octavia_ca.yml
index 453c450..e6e0ae0 100644
--- a/salt/minion/ca/octavia_ca.yml
+++ b/salt/minion/ca/octavia_ca.yml
@@ -27,7 +27,5 @@
           days_valid:
             authority: ${_param:octavia_ca_days_valid_authority}
             certificate: ${_param:octavia_ca_days_valid_certificate}
-          ca_file: ${octavia:manager:certificates:ca_certificate}
-          ca_key_file: ${octavia:manager:certificates:ca_private_key}
           user: octavia
           group: octavia