Move location of HTTPException in swift_testing

While doing some work around swiftclient Python 3 support, httplib
imports were changed to use six.moves in order to access httplib in Py2
and http.client in Py3. Tests related to those changes are failing
because these functional tests are depending on HTTPException being
a name in swiftclient.client. These tests should acces that name from
its canonical location in httplib (or, eventually, a Py3 friendly
location like six.moves).

Change-Id: I6335d465574045daedab47e5fe23c415d171a83a

test/functionalnosetests/swift_testing.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from httplib import HTTPException
 import os
 import socket
 import sys
@@ -20,7 +21,7 @@ from time import sleep
 
 from test import get_config
 
-from swiftclient import get_auth, http_connection, HTTPException
+from swiftclient import get_auth, http_connection
 
 conf = get_config('func_test')
 web_front_end = conf.get('web_front_end', 'integral')