removing decrement of cardinality in quickcheck -- counting cardinalities starts at 1

--- a/src/Tools/quickcheck.ML	Thu Apr 07 14:51:26 2011 +0200
+++ b/src/Tools/quickcheck.ML	Thu Apr 07 14:51:28 2011 +0200
@@ -340,7 +340,7 @@
       (* FIXME: why decrement size by one? *)
       let
         val (ts, timing) = cpu_time ("size " ^ string_of_int size ^ " and card " ^ string_of_int card)
-          (fn () => fst (test_fun [card - 1, size - 1]))
+          (fn () => fst (test_fun [card, size - 1]))
         val _ = add_timing timing current_result
       in
         Option.map (pair card) ts