Getwork with unknown location should return an HTTP error

If I try to get work for an unknown location, e.g.:
   wget -S -O - www.webpagetest.org/work/getwork.php?location=blah

I get back an HTTP success:
    HTTP/1.1 200 OK
    ...

which is exactly the same response for valid locations with no pending jobs.  
This makes it difficult to detect configuration errors in the client and/or 
server (settings/location.ini).

Instead, the server should respond with something like:
    HTTP/1.1 403 Forbidden
    ...
    [put a list of valid locations here, format TBD]

Original issue reported on code.google.com by wrig...@google.com on 16 May 2013 at 3:41

tsuyopon / webpagetest

Getwork with unknown location should return an HTTP error #155