Enable proxy header parsing for Manila

This is necessary for when HAProxy is terminating TLS for manila,
else we will have keystone discovery errors. This is the same we do
for several other services, as manila uses the same middleware.

Change-Id: Ice78b0abceb6a956bb8c1dc6212ee1b56b62b43f

puppet/services/manila-api.yaml

@@ -66,6 +66,7 @@ outputs:
             # internal_api_uri -> [IP]
             # internal_api_subnet - > IP/CIDR
             manila::api::bind_host: {get_param: [ServiceNetMap, ManilaApiNetwork]}
+            manila::api::enable_proxy_headers_parsing: true
       step_config: |
         include ::tripleo::profile::base::manila::api