Remove unused variable

o heat/common/config.py:DEFAULT_PORT = 8000

  This variable was removed in the following commit.

    commit 34e47b64d926c055d9895c5b3f27949eaca68999
    Author: Steve Baker <sbaker@redhat.com>
    Date:   Mon Jul 22 16:01:44 2013 +1200

        Move heat-cfn, heat-boto, heat-watch to new repo

Change-Id: Iab6213eba1422882c92bd16a3351df19869aa9f3
Merge "Remove unused variable"