Return dict not protobuf message for ffs.default_config()

[peterVG]

Right now the user of the grpc-client has to import and use MessageToDict() from google.protobuf.json_format to convert the protobuf message to a Python dictionary. This should be abstracted away and done in the client which should just return a dictionary to the script calling ffs.default_config().

Note, this has already been done for the ffs.set_default_config() method. See https://github.com/pygate/pygate-gRPC/blob/84554d50fe6fabe259b45e4acd889aebe23ae308/pygate_grpc/ffs.py#L84