Fixing trigger gravity

Currently the trigger_gravity brush entity doesn't actually function properly.

To fix gravity triggers, navigate to triggers.cpp, around line 2679 and find this:

void CTriggerGravity::GravityTouch( CBaseEntity *pOther )
{
	// Only save on clients
	if ( !pOther->IsPlayer() )
		return;

	pOther->SetGravity( GetGravity() );
}

and either comment out or remove the if-return.

trigger_gravity should work fine now on players, but still won't change a physics object's gravity.