Fix issue #480

[giang-nghg]

No description provided.

[adaschevici]

Hi @giang271291,
There seems to be a test failing because of this change most likely.
Could you fix it?
Traceback:

FAIL: Test django httpd threading

Traceback (most recent call last):
File "/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/nose/case.py", line 197, in runTest
self.test(*self.arg)
File "/home/travis/build/gabrielfalcao/lettuce/tests/unit/test_server.py", line 33, in test_server_threading
assert_equals(status, 0, out)
AssertionError: Usage: manage.py harvest [options] [PATH to feature file or folder]

Thanks