Only create consent sheet if required

src/qml/main.qml

@@ -259,8 +259,9 @@ Kirigami.ApplicationWindow {
         }
 
         function onUserConsentRequired(url) {
-            consentSheet.url = url
+            let consent = consentSheetComponent.createObject(QQC2.ApplicationWindow.overlay)
-            consentSheet.open()
+            consent.url = url
+            consent.open()
         }
     }
 
@@ -301,6 +302,8 @@ Kirigami.ApplicationWindow {
         }
     }
 
+    Component {
+        id: consentSheetComponent
         Kirigami.OverlaySheet {
             id: consentSheet
 
@@ -320,6 +323,7 @@ Kirigami.ApplicationWindow {
                 onClicked: UrlHelper.openUrl(consentSheet.url)
             }
         }
+    }
 
     Component {
         id: createRoomDialog