Fix link in last commit for system-backdrop-controller.md

Author: MuyuanMS

hub/apps/windows-app-sdk/system-backdrop-controller.md

@@ -217,7 +217,7 @@ The controller reacts to the system Light and Dark themes by default. To overrid
 
 > [!NOTE]
 >
-> After customizing any of the controller’s four properties, it no longer applies default Light or Dark values when the associated [SystemBackdropConfiguration.Theme](/windows/windows-app-sdk/api/winrt/microsoft.ui.composition.systembackdrops.systembackdropconfiguration.theme?view=windows-app-sdk-1.6#microsoft-ui-composition-systembackdrops-systembackdropconfiguration-theme) changes. You need to manually update those properties to match the new theme.
+> After customizing any of the controller’s four properties, it no longer applies default Light or Dark values when the associated [SystemBackdropConfiguration.Theme](/windows/windows-app-sdk/api/winrt/microsoft.ui.composition.systembackdrops.systembackdropconfiguration.theme) changes. You need to manually update those properties to match the new theme.
 
 In order to use the backdrop material in your app, the following items are required: