Turned off the test case for bug 49322 when join_cache_level=6.

It should be turned on back when the tree for MWL#128 is merged
into the main 5.3 merge.

mysql-test/t/join_nested.test

@@ -1196,6 +1196,9 @@ SELECT COUNT(*)
 
 DROP TABLE t1,t2,t3,t4,t5;
 
+# !!!Remove the following if brackets after having merged the code of MWL#128 
+if (`SELECT @@join_cache_level=1`)
+{  
 #
 # BUG#49322: Nested left joins + not-exist optimization
 #
@@ -1235,6 +1238,7 @@ SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a
   WHERE t3.pk IS NULL;
 
 DROP TABLE t1, t2, t3;
+}
 
 --echo End of 5.0 tests