Fix missing Window on iOS

Broken by 9e6e59276b

Passepartout/App/PassepartoutApp.swift

@@ -48,7 +48,17 @@ struct PassepartoutApp: App {
     private var theme = Theme()
 
     var body: some Scene {
-        Window(appName, id: appName) {
+#if os(iOS)
+        WindowGroup(content: content)
+#else
+        Window(appName, id: appName, content: content)
+            .defaultSize(width: 600.0, height: 400.0)
+#endif
+    }
+}
+
+private extension PassepartoutApp {
+    func content() -> some View {
         AppCoordinator(
             profileManager: context.profileManager,
             tunnel: context.tunnel,
@@ -66,8 +76,4 @@ struct PassepartoutApp: App {
         .environmentObject(context.iapManager)
         .environmentObject(context.connectionObserver)
     }
-#if os(macOS)
-        .defaultSize(width: 600.0, height: 400.0)
-#endif
-    }
 }