[gnuoy,trivial] Fix charm proof warning

config.yaml

@@ -63,6 +63,7 @@ options:
   # User provided SSL cert and key
   ssl_cert:
     type: string
+    default:
     description: |
       Base64 encoded SSL certificate to install and use for API ports.
       .
@@ -75,6 +76,7 @@ options:
       do so).
   ssl_key:
     type: string
+    default:
     description: |
       Base64 encoded SSL key to use with certificate specified as ssl_cert.
   # General Swift Proxy configuration
@@ -117,6 +119,7 @@ options:
   # Manual Keystone configuration.
   keystone-auth-host:
     type: string
+    default:
     description: Keystone authentication host
   keystone-auth-port:
     default: 35357
@@ -132,16 +135,20 @@ options:
     description: Keystone admin tenant name
   keystone-admin-user:
     type: string
+    default:
     description: Keystone admin username
   keystone-admin-password:
     type: string
+    default:
     description: Keystone admin password
   # HA configuration settings
   swift-hash:
     type: string
+    default:
     description: Hash to use across all swift-proxy servers - don't loose
   vip:
     type: string
+    default:
     description: |
       Virtual IP(s) to use to front API services in HA configuration.
       .
@@ -163,6 +170,7 @@ options:
   # by default all access is over 'private-address'
   os-admin-network:
     type: string
+    default:
     description: |
       The IP address and netmask of the OpenStack Admin network (e.g.,
       192.168.0.0/24)
@@ -170,6 +178,7 @@ options:
       This network will be used for admin endpoints.
   os-internal-network:
     type: string
+    default:
     description: |
       The IP address and netmask of the OpenStack Internal network (e.g.,
       192.168.0.0/24)
@@ -177,6 +186,7 @@ options:
       This network will be used for internal endpoints.
   os-public-network:
     type: string
+    default:
     description: |
       The IP address and netmask of the OpenStack Public network (e.g.,
       192.168.0.0/24)