Disable more tests in Python2.6, because of set literals that don't exist there.

test/completion/arrays.py

@@ -366,8 +366,6 @@ tuple(a)[1]
 #? int() str()
 tuple(list(set(a)))[1]
 
-#? int()
-tuple({1})[0]
 #? int()
 tuple((1,))[0]
 
@@ -404,6 +402,12 @@ def test_func():
     #? str()
     x
 
+
+# python >= 2.7
+# Set literals are not valid in 2.6.
+#? int()
+tuple({1})[0]
+
 # python >= 3.3
 # -----------------
 # PEP 3132 Extended Iterable Unpacking (star unpacking)