"web.subdomain_application" is broken

Since rev232, I noticed a trouble with the domain dispatcher "web.subdomain_application" which seems to route to 404.
It worked in the past ...

And the doctest in application.py seems to point the trouble :

File "application.py", line 428, in __main__.subdomain_application
Failed example:
    app2.request("/hello", host="hello.example.com").data
Expected:
    'hello'
Got:
    'not found'
**********************************************************************
1 items had failures:
   1 of 9 in __main__.subdomain_application
***Test Failed*** 1 failures.