Don't fail on location-less events

We can end up there with online events for example.

src/app/EventDelegate.qml

@@ -42,7 +42,7 @@ App.TimelineDelegate {
         spacing: Kirigami.Units.smallSpacing
 
         QQC2.Label {
-            text: reservationFor.location.name
+            text: reservationFor.location != undefined ? reservationFor.location.name : ""
         }
         App.PlaceDelegate {
             place: reservationFor.location
@@ -50,6 +50,7 @@ App.TimelineDelegate {
             isRangeBegin: root.rangeType == TimelineElement.RangeBegin
             isRangeEnd: root.rangeType == TimelineElement.RangeEnd
             width: topLayout.width
+            visible: reservationFor.location != undefined
         }
         QQC2.Label {
             text: i18n("Start time: %1", Localizer.formatDateTime(reservationFor, "startDate"))

src/app/EventPage.qml

@@ -42,12 +42,14 @@ App.DetailsPage {
 
             QQC2.Label {
                 Kirigami.FormData.label: i18n("Location:")
-                text: reservationFor.location.name
+                text: reservationFor.location != undefined ? reservationFor.location.name : ""
+                visible: reservationFor.location != undefined
             }
 
             App.PlaceDelegate {
                 place: reservationFor.location
                 controller: root.controller
+                visible: reservationFor.location != undefined
             }
 
             QQC2.Label {