fix TransitionGroup children have to be keyed when adding a new widget to dashboard

public/js/components/Dashboard/Dashboard.js

@@ -55,6 +55,7 @@ export default {
 			}
 			this.$refs.widgetpicker.getWidget().then(widget_id => {
 				widget.widget = widget_id;
+				widget.id = 'loading_' + String((new Date()).valueOf());
 				let loading = {...widget};
 				loading.loading = true;
 				this.sections.forEach(section => {
@@ -176,4 +177,4 @@ export default {
 		<dashboard-section v-for="(section, index) in sections" :key="section.name" :seperator="index" :name="section.name" :widgets="section.widgets" @widgetAdd="widgetAdd" @widgetUpdate="widgetUpdate" @widgetRemove="widgetRemove"></dashboard-section>
 		<dashboard-widget-picker ref="widgetpicker" :widgets="widgets"></dashboard-widget-picker>
 	</div>`
-}
+}