fix

server/handler.go

@@ -80,7 +80,7 @@ func Handler(mainDomainSuffix, rawDomain string,
 
 		ctx.RespWriter.Header().Set("Allow", http.MethodGet+", "+http.MethodHead+", "+http.MethodOptions) // duplic 1
 		if ctx.IsMethod(http.MethodOptions) {
-			ctx.Response().StatusCode = http.StatusNoContent
+			ctx.RespWriter.WriteHeader(http.StatusNoContent)
 			return
 		}