Rename peer S3 prefix to avoid collision in the future (#16473)

cmd/handler-utils.go

@@ -403,6 +403,12 @@ func errorResponseHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	desc := "Do not upgrade one server at a time - please follow the recommended guidelines mentioned here https://github.com/minio/minio#upgrading-minio for your environment"
 	switch {
+	case strings.HasPrefix(r.URL.Path, peerS3Prefix):
+		writeErrorResponseString(r.Context(), w, APIError{
+			Code:           "XMinioPeerS3VersionMismatch",
+			Description:    desc,
+			HTTPStatusCode: http.StatusUpgradeRequired,
+		}, r.URL)
 	case strings.HasPrefix(r.URL.Path, peerRESTPrefix):
 		writeErrorResponseString(r.Context(), w, APIError{
 			Code:           "XMinioPeerVersionMismatch",