Fix misleading example for user_runtime_directory.

borgmatic/config/schema.yaml

@@ -219,7 +219,7 @@ properties:
             dumps and bootstrap metadata. borgmatic automatically creates and
             uses a "borgmatic" subdirectory here. Defaults to $XDG_RUNTIME_DIR
             or or $TMPDIR or $TEMP or /run/user/$UID.
-        example: /run/user/1001/borgmatic
+        example: /run/user/1001
     user_state_directory:
         type: string
         description: |