Just play the game and find out if it was *****ing at you for no reason. I once had half life 2 episode 2 *****ing at me because i didn't have a 2.2ghz processor, but rather a lowly 2.0ghzz
Surely enough my game played fine. This is as easy as calling the games bluff. And that's where you find out if it was bluffing or not. It's not like calling a game's bluff is going to be volatile for your computer.
EDIT: It also really helps to know your system's specs. We have no idea what allocated memory gta is *****ing about. Expect no more help from what we gave you so far until you do give your system's specs (we don't know enough to help you).