windows packaging: Fix productcode

Author: NickeZ

bitbox-bridge/release/windows/wix/Product.wxs

@@ -6,7 +6,7 @@
   <!-- UpgradeCode should stay the same foverever (this is the real ID of the app)-->
   <?define UpgradeCode = "{dfe7eecb-5dc0-4c30-ba78-a9eff36efa31}"?>
 
-  <Product Id="{7daf2692-5978-41fe-8148-61bef4aa3ae2}"
+  <Product Id="$(var.ProductCode)"
     Name="!(loc.ProductName)"
     Language="!(loc.Language)"
     Version="$(env.VERSION)"