message: Fix to remove listener
diff: @@ -25,7 +25,7 @@ export class SchamaJsonManager {
  registerOnChange(cb: (schema: any) => void) {
  this._onChanges.push(cb);
  return () => {
  - this._onChanges.filter(x => x !== cb);
  + this._onChanges = this._onChanges.filter(x => x !== cb);
  };
  }
  