server: remove unparsed body from request and message

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

message.go

@@ -18,10 +18,6 @@ func (r *httpMessage) Topic() string {
 	return r.topic
 }
 
-func (r *httpMessage) Payload() interface{} {
-	return r.payload
-}
-
 func (r *httpMessage) ContentType() string {
 	return r.contentType
 }
@@ -30,8 +26,8 @@ func (r *httpMessage) Header() metadata.Metadata {
 	return r.header
 }
 
-func (r *httpMessage) Body() []byte {
-	return r.body
+func (r *httpMessage) Body() interface{} {
+	return r.payload
 }
 
 func (r *httpMessage) Codec() codec.Codec {