[1.2.X] Modified the sitemaps tests to remove an assumption about the...

[1.2.X] Modified the sitemaps tests to remove an assumption about the environment in which the tests are run. Thanks to Gabriel Hurley for the report and patch.

Backport of r14184 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14185 bcc190cf-cafb-0310-a4f2-bffc1f526a37