message: fix config dump docs
diff: @@ -155,14 +155,14 @@ modify different aspects of the server:
  .. _operations_admin_interface_config_dump_by_resource_and_mask:
  -.. http:get:: /config_dump?resource={},mask={}
  +.. http:get:: /config_dump?resource={}&mask={}
  When both resource and mask query parameters are specified, the mask is applied to every element
  in the desired repeated field so that only a subset of fields are returned. The mask is parsed
  as a ``ProtobufWkt::FieldMask``.
  For example, get the names of all active dynamic clusters with
  - ``/config_dump?resource=dynamic_active_clusters,mask=cluster.name``
  + ``/config_dump?resource=dynamic_active_clusters&mask=cluster.name``
  .. http:get:: /contention
  