feat(serverHandler/json): add extra header

Author: marjune163

src/serverHandler/json.go

@@ -78,6 +78,7 @@ func getJsonData(data *responseData) *jsonResponseData {
 func (h *aliasHandler) json(w http.ResponseWriter, r *http.Request, data *responseData) {
 	header := w.Header()
 	header.Set("Vary", h.vary)
+	header.Set("X-Content-Type-Options", "nosniff")
 	header.Set("Content-Type", "application/json; charset=utf-8")
 	if lacksHeader(header, "Cache-Control") {
 		header.Set("Cache-Control", "public, max-age=0")