removing setuptools module names from user warnings

--HG--
branch : distribute
extra : rebase_source : f20f663e7122029c873fde4df0b076697d3c4a44

pkg_resources.py

@@ -2263,7 +2263,8 @@ class Distribution(object):
                 or modname in _namespace_packages
             ):
                 continue
-
+            if modname in ('pkg_resources', 'setuptools', 'site'):
+                continue
             fn = getattr(sys.modules[modname], '__file__', None)
             if fn and normalize_path(fn).startswith(loc):
                 continue