adds pending state to alert list panel

public/app/plugins/panel/alertlist/editor.html

@@ -50,5 +50,6 @@
     <gf-form-switch class="gf-form" label="No data" label-class="width-10" checked="ctrl.stateFilter['no_data']" on-change="ctrl.updateStateFilter()"></gf-form-switch>
     <gf-form-switch class="gf-form" label="Execution error" label-class="width-10" checked="ctrl.stateFilter['execution_error']" on-change="ctrl.updateStateFilter()"></gf-form-switch>
     <gf-form-switch class="gf-form" label="Alerting" label-class="width-10" checked="ctrl.stateFilter['alerting']" on-change="ctrl.updateStateFilter()"></gf-form-switch>
+    <gf-form-switch class="gf-form" label="Pending" label-class="width-10" checked="ctrl.stateFilter['pending']" on-change="ctrl.updateStateFilter()"></gf-form-switch>
   </div>
 </div>