Can I suggest that it shouldn't do this. The GPL is not an EULA; it actually does not apply to an end user. I quote from it here:
Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does.
Installation of a software product in order to run it does not count as copying in most countries; it is usually explicitly allowed either by relevant legislation or court precedents.
It therefore seems redundant to make an end user, who likely won't redistribute the program, indicate that he accepts the licence. And given that he can legally only redistribute the program if he accepts the licence, it certainly isn't a necessity in even that case.