Nerf intellenct bonus of classical music for mp3 player

As discussed in #8026, mp3 players could easily reach 100 morale bonus with the use of an atomic battery mod if a player had 10+ INT. This PR reduces that bonus, to 50 + INT*2. So a 10 INT player will get up to 60, and the limit of 25 would get 100. There is still a cap on stats at 25, right...?