fix: don't try to export empty report (#9482)

frappe/desk/query_report.py

@@ -303,6 +303,11 @@ def export_query():
 	if file_format_type == "Excel":
 		data = run(report_name, filters)
 		data = frappe._dict(data)
+		if not data.columns:
+			frappe.respond_as_web_page(_("No data to export"),
+			_("You can try changing the filters of your report."))
+			return
+
 		columns = get_columns_dict(data.columns)
 
 		from frappe.utils.xlsxutils import make_xlsx