Fix Player 2 Start Button Crash

Pressing p2 start in music select crashes the game for "no reason." Here's the reason. It's fixed (disabled).

src/ScreenSelectMusic.cpp

@@ -585,14 +585,15 @@ bool ScreenSelectMusic::Input(const InputEventPlus &input)
 	if (!input.GameI.IsValid())
 		return false; // don't care
 
-					  // Handle late joining
-					  // If the other player is allowed to join on the extra stage, then the
-					  // summary screen will crash on invalid stage stats. -Kyz
+	/**** This handles letting player 2 into the game after that old screen that we haven't seen in 25 years
+	* you know, the one that lets you pick how many people you are playing with.
+	* Anyways, let's disable this block because all it does is crash the game now.
 	if (m_SelectionState != SelectionState_Finalized &&
 		input.MenuI == GAME_BUTTON_START && input.type == IET_FIRST_PRESS && GAMESTATE->JoinInput(input.pn))
 	{
 		return true; // don't handle this press again below
 	}
+	*/
 
 	if (!GAMESTATE->IsHumanPlayer(input.pn))
 		return false;