Don't load leaflet in the background.

This was causing it to be the wrong size and not load tiles (Closes #21)

src/views/Event/EventView.vue

@@ -261,6 +261,7 @@
       >
         <template #default>
           <event-map
+            v-if="showMap"
             :routingType="routingType ?? RoutingType.OPENSTREETMAP"
             :address="event.physicalAddress"
             @close="showMap = false"