Technically, thats not needed for GPLed software, the GPL remains valid even without the explicit click of the user.
See GPL v2 FAQ and GPL v3
Some software packaging systems have a place which requires you to click through or otherwise indicate assent to the terms of the GPL. This is neither required nor forbidden. With or without a click through, the GPL's rules remain the same.
Merely agreeing to the GPL doesn't place any obligations on you. You are not required to agree to anything to merely use software which is licensed under the GPL. You only have obligations if you modify or distribute the software. If it really bothers you to click through the GPL, nothing stops you from hacking the GPLed software to bypass this