[FIX] no rollback when adding unremovable node

Author: Emilien Durieu (edu)

src/editor.js

@@ -327,9 +327,6 @@ export class OdooEditor extends EventTarget {
                 }
                 case 'childList': {
                     record.addedNodes.forEach(added => {
-                        this._toRollback =
-                            this._toRollback ||
-                            (containsUnremovable(added) && UNREMOVABLE_ROLLBACK_CODE);
                         const mutation = {
                             'type': 'add',
                         };