monaco_editor: fix offset in pylint diagnostics

when fixing coding style in 0b8b8475 (administration,core: wrong
location when reporting pylint errors, 2024-05-25) it became wrong here.

bt5/erp5_monaco_editor/SkinTemplateItem/portal_skins/erp5_monaco_editor/monaco_editor_support.zpt

@@ -242,8 +242,8 @@ $script.onload = function() {
           "pylint",
           data["annotations"].map(annotation => {
             return {
-              startLineNumber: annotation.row + 1,
-              endLineNumber: annotation.row + 1,
+              startLineNumber: annotation.row,
+              endLineNumber: annotation.row,
               startColumn: annotation.col,
               endColumn: Infinity,
               message: annotation.text,