message: Monitoring: Remove broken Silenced By list column header links
  `SilenceHeader` showed the correct column headings, but as clickable
  links. The Silenced By table is not sortable, so the column headings
  should not be links.
diff: @@ -256,7 +256,11 @@ const AlertsDetailsPage = withFallback(connect(alertStateToProps)((props: Alerts
  <div className="row">
  <div className="col-xs-12">
  <div className="co-m-table-grid co-m-table-grid--bordered">
  - <SilenceHeader />
  + <div className="row co-m-table-grid__head">
  + <div className="col-xs-7">Name</div>
  + <div className="col-xs-3">State</div>
  + <div className="col-xs-2">Firing Alerts</div>
  + </div>
  <div className="co-m-table-grid__body">
  {_.map(silencedBy, s => <SilenceRow key={s.id} obj={s} />)}
  </div>
  