Remove mention of Traits (removed in e1ced0b3)

IPython/utils/dir2.py

@@ -34,7 +34,7 b' def dir2(obj):'
     """dir2(obj) -> list of strings
 
     Extended version of the Python builtin dir(), which does a few extra
-    checks, and handles Traits objects, which can confuse dir().
+    checks.
 
     This version is guaranteed to return only a list of true strings, whereas
     dir() returns anything that objects inject into themselves, even if they