message: don't crash when a column cannot be cleared
diff: @@ -111,9 +111,15 @@ export const maybeAddColumnsButtons = makeBTDModule(({TD, jq, settings}) => {
  jq('body').on('click', '.btd-clear-all-columns', () => {
  const confirmed = confirm('This will clear ALL the columns, are you sure you want to do it?');
  - if (confirmed) {
  - TD.controller.columnManager.getAllOrdered().forEach((c) => c.clear());
  + if (!confirmed) {
  + return;
  + }
  + TD.controller.columnManager.getAllOrdered().forEach((c) => {
  + if (!c.clear) {
  + return;
  }
  + c.clear();
  + });
  });
  const columnsSettings = getCollapsedColumnState();
  