Fix test-only bug in script test

Previously conflict_set.py only worked for checking one read conflict
per call

test_conflict_set.py

@@ -53,7 +53,7 @@ def test_conflict_set():
         assert cs.getBytes() - before > 0
         assert cs.check(read(0, key)) == [Result.CONFLICT]
         cs.setOldestVersion(1)
-        assert cs.check(read(0, key)) == [Result.TOO_OLD]
+        assert cs.check(read(0, key), read(1, key)) == [Result.TOO_OLD, Result.COMMIT]
 
 
 def test_inner_full_words():