Fix PLAYER:AddCount() causing PLAYER:GetCount() to report incorrect values

About the issue: 
http://facepunch.com/showthread.php?t=1348923&p=44954712&viewfull=1#post44954712
http://facepunch.com/showthread.php?t=1348923&p=44954892&viewfull=1#post44954892
http://facepunch.com/showthread.php?t=1348923&p=44955078&viewfull=1#post44955078

Somehow this only became an issue within the last 2 months even though this file hasn't been edited for a year. 

Anyway, the whole 'minus' part about PLAYER:GetCount() and PLAYER:AddCount() is redundant because PLAYER:GetCount() already sanitizes the table of props and gets an accurate number. By subtracting 1 afterward, it is actually breaking it.