Fix certificates creation for image sign

Change-Id: I60984a2badac898b4d375dd22981e4b303f8f5db
Related-PROD: PROD-25719
diff --git a/salt/minion/cert/octavia/image_sign.yml b/salt/minion/cert/octavia/image_sign.yml
index 2e67a02..ad7cfd0 100644
--- a/salt/minion/cert/octavia/image_sign.yml
+++ b/salt/minion/cert/octavia/image_sign.yml
@@ -1,17 +1,15 @@
-classes:
-- system.salt.minion.cert.octavia
 parameters:
   _param:
+    salt_minion_ca_authority: salt_master_ca
     octavia_image_cert_key: /etc/octavia/certs/image.key
     octavia_image_cert_file: /etc/octavia/certs/image.crt
   salt:
     minion:
       cert:
         octavia:
-          host: ${_param:octavia_ca_host}
-          authority: octavia_ca
+          host: ${_param:salt_minion_ca_host}
+          authority: ${_param:salt_minion_ca_authority}
           common_name: octavia
           signing_policy: cert_server
-          key_usage: "digitalSignature,nonRepudiation,keyEncipherment"
           key_file:  ${_param:octavia_image_cert_key}
           cert_file: ${_param:octavia_image_cert_file}
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