require_stat script: do not force unequip anymore:

 * Using unequipbyid was causing a temporary x2 bonus on most stats
   of the player, which appeared to be exploitable in one case.
 * Fallback on keeping the item equiped but do not activate its bonuses.

world/map/npc/items/require_stat.txt

@@ -21,7 +21,7 @@ function|script|RequireStat|{
     if (@bStat$ == "Luk")
         set @bStatVal, readParam(bLuk);
     if (@bStatVal >= @minbStatVal) return;
-    message strcharinfo(0), "You do not see how to use this item properly.";
-    unequipbyid @slotId;
+    // If the requirement isn't met, then we end the script.
+    // Hence, subsequent item modifiers won't be applied.
     end;
 }