V1.10 - Less prominent mouse controls

I'm noticing that players are using the mouse controls by default, when they were only added as backup for when you want a 4th player but don't have any controllers. The mouse controls can be a bit difficult to use, so for now it only shows mouse controls as an input if all the player slots are filled except the last one.

Changelog:
CHANGED - Prompt to use mouse controls on lobby only shows if there’s 1 player slot left