message: Hide Delete Backup button when Secure Backup required
  If Secure Backup is required by the HS admin, then this hides the Delete Backup
  button in Settings to ensure everyone keeps their backup per policy.
  Part of
diff: @@ -21,6 +21,7 @@ import * as sdk from '../../../index';
  import {MatrixClientPeg} from '../../../MatrixClientPeg';
  import { _t } from '../../../languageHandler';
  import Modal from '../../../Modal';
  +import { isSecureBackupRequired } from '../../../utils/WellKnownUtils';
  export default class KeyBackupPanel extends React.PureComponent {
  constructor(props) {
  @@ -315,14 +316,19 @@ export default class KeyBackupPanel extends React.PureComponent {
  trustedLocally = _t("This backup is trusted because it has been restored on this session");
  }
  + let deleteBackupButton;
  + if (!isSecureBackupRequired()) {
  + deleteBackupButton = <AccessibleButton kind="danger" onClick={this._deleteBackup}>
  + {_t("Delete Backup")}
  + </AccessibleButton>;
  + }
  +
  const buttonRow = (
  <div className="mx_KeyBackupPanel_buttonRow">
  <AccessibleButton kind="primary" onClick={this._restoreBackup}>
  {restoreButtonCaption}
  </AccessibleButton>&nbsp;&nbsp;&nbsp;
  - <AccessibleButton kind="danger" onClick={this._deleteBackup}>
  - {_t("Delete Backup")}
  - </AccessibleButton>
  + {deleteBackupButton}
  </div>
  );
  