fix: bug in 8.9.1 with Save as dialog (don`t loaded page tree)

src/main/java/onlyoffice/OnlyOfficeEditorServlet.java

@@ -183,6 +183,7 @@ public void doGet(final HttpServletRequest request, final HttpServletResponse re
 
                 ObjectMapper mapper = new ObjectMapper();
 
+                context.put("request", request);
                 context.put("configAsHtml", mapper.writeValueAsString(config));
                 context.put("historyInfoUriAsHtml", urlManager.getHistoryInfoUri(attachmentId));
                 context.put("historyDataUriAsHtml", urlManager.getHistoryDataUri(attachmentId));