Latest dev appengine server defaults admin port to 8000
which isn't always available and can cause spurious
failures.

R=maruel@chromium.org

Review URL: https://chromiumcodereview.appspot.com/20904002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@214050 0039d316-1c4b-4281-b951-d872f2087c98