Make effective ssl callback behaviour more obvious

When using 'insecure' no callback is executed.

Make it more obvious that the set_verify callback
won't be called by replacing it with a lambda.

Fixes bug 1112361.

Change-Id: Ib5d43a8883f7ed76383971d8154e2111f5ab2869

glanceclient/common/http.py

@@ -317,7 +317,7 @@ class VerifiedHTTPSConnection(httplib.HTTPSConnection):
                                     self.verify_callback)
         else:
             self.context.set_verify(OpenSSL.SSL.VERIFY_NONE,
-                                    self.verify_callback)
+                                    lambda *args: True)
 
         if self.cert_file:
             try: