Warn to console, not flash, when performance bar fails

This isn't interesting most of the time and is may go over other flash banners.

app/assets/javascripts/performance_bar/index.js

 import Vue from 'vue';
-import Flash from '../flash';
 import PerformanceBarService from './services/performance_bar_service';
 import PerformanceBarStore from './stores/performance_bar_store';
@@ -46,7 +45,8 @@ export default ({ container }) =>
             this.store.addRequestDetails(requestId, res.data.data);
           })
           .catch(() =>
-            Flash(`Error getting performance bar results for ${requestId}`),
+            // eslint-disable-next-line no-console
+            console.warn(`Error getting performance bar results for ${requestId}`),
           );
       },
     },