Removed testcase to assert IAE when relativeSD>3.7

Author: Vinod K C

python/pyspark/tests.py

@@ -644,7 +644,6 @@ def test_count_approx_distinct(self):
         self.assertTrue(18 < rdd.map(lambda x: (x, -x)).countApproxDistinct() < 22)
 
         self.assertRaises(ValueError, lambda: rdd.countApproxDistinct(0.00000001))
-        self.assertRaises(ValueError, lambda: rdd.countApproxDistinct(0.5))
 
     def test_histogram(self):
         # empty