CA-95645: fix Python 2.6 type error comparing DateTime

We compare the result of an rpc call with a constant called
_RECONNECT_AND_RETRY (which was just set to an anonymous function) to decide if
we need to retry the rpc call. When the result is a DateTime object, and we're
using python 2.6+, this comparison (using ==) throws an exception.

The fix is to use the 'is' operator instead of '==', so that we're testing
object equality, and not structural equality. We also set the
_RECONNECT_AND_RETRY constant to object(), which is more sensible than (lambda
_ : ()).

Signed-off-by: Mike McClurg <mike.mcclurg@citrix.com>
Merge pull request #1029 from mcclurmc/clearwater-CA-95645

CA-95645: fix Python 2.6 type error comparing DateTime