you don't select a stack for custom conatiners

Author: btardif

articles/app-service/configure-common.md

@@ -421,7 +421,7 @@ Here, you can configure some common settings for the app. Some settings require
 
 - **Stack settings**: The software stack to run the app, including the language and SDK versions.
 
-    For Linux apps and custom containers, you can select the language runtime version and set an optional **Startup command** or a startup command file.
+    For Linux apps, you can select the language runtime version and set an optional **Startup command** or a startup command file.
 
     ![General settings for Linux containers](./media/configure-common/open-general-linux.png)