I ran the installer now, and I confirm the problem doesn't happen.
In any case, it's not really an issue, the only reason to patch that file, is to remove the default pushback truck so you might just see two pushback truck (GSX and default) but since they don't start in the same place, this is not a problem and won't have any effect on GSX operations.
You can achieve the same results by turning down your default airport ground traffic slider, so you'll only have GSX vehicles in any case.