Merge pull request 'copy incoming content-type' (#177) from ct into v3

Reviewed-on: #177

handler/swagger/swagger.go

@@ -29,6 +29,12 @@ var Handler = func(dst map[string]interface{}, fsys fs.FS) http.HandlerFunc {
 			return
 		}
 
+		if dst == nil {
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write(buf)
+			return
+		}
+
 		var src interface{}
 
 		if err = c.Unmarshal(buf, src); err != nil {

subscriber.go

@@ -111,7 +111,6 @@ func (s *Server) createSubHandler(sb *httpSubscriber, opts server.Options) broke
 		}
 
 		hdr := metadata.Copy(msg.Header)
-		delete(hdr, "Content-Type")
 		ctx := metadata.NewIncomingContext(context.Background(), hdr)
 
 		results := make(chan error, len(sb.handlers))