Fix: DATA-2220
(PF/APG) Masterspy Sneak Attack Progresses Too Quickly

 (MasterSpyLVL-1/3)+1 to ((MasterSpyLVL-1)/3)+1

git-svn-id: svn+ssh://svn.code.sf.net/p/pcgen/code/Trunk@25678 ef53c05b-3124-4d59-ae7d-fe3273f42be7