### Please describe the problem.

[[This|design/assistant/blog/day_314__quvi/]] says that I can download youtube videos with git-annex, but I can't - it downloads the HTML of the page instead!

### What steps will reproduce the problem?

    git annex addurl http://www.youtube.com/watch?v=BTzNLhxPzjo

Should have downloaded a Bill Hicks video, instead it downloads the HTML.

### What version of git-annex are you using? On what operating system?

[[!format txt """
git-annex version: 4.20130912-ga1faca3
build flags: Assistant Webapp Pairing Testsuite S3 WebDAV Inotify DBus XMPP DNS Feeds Quvi
local repository version: 3
default repository version: 3
supported repository versions: 3 4
upgrade supported from repository versions: 0 1 2
"""]]

Note that quvi is still capable of fetching that video, no problem there.

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log
anarcat@marcos:clips$ git annex addurl http://www.youtube.com/watch?v=BTzNLhxPzjo
addurl www.youtube.com_watch_v=BTzNLhxPzjo ok
anarcat@marcos:clips$ file www.youtube.com_watch_v\=BTzNLhxPzjo
www.youtube.com_watch_v=BTzNLhxPzjo: broken symbolic link to `.git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b'
anarcat@marcos:clips$ file www.youtube.com_watch_v\=BTzNLhxPzjo ^C
anarcat@marcos:clips$ file .git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b
.git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b: ERROR: cannot open `.git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b' (No such file or directory)
anarcat@marcos:clips$ git annex get www.youtube.com_watch_v\=BTzNLhxPzjo
get www.youtube.com_watch_v=BTzNLhxPzjo (from web...)
--2013-09-14 17:24:23--  http://www.youtube.com/watch?v=BTzNLhxPzjo
Résolution de www.youtube.com (www.youtube.com)... 173.194.43.96, 173.194.43.97, 173.194.43.98, ...
Connexion vers www.youtube.com (www.youtube.com)|173.194.43.96|:80...connecté.
requête HTTP transmise, en attente de la réponse...200 OK
Longueur: non spécifié [text/html]
Sauvegarde en : «/srv/video/clips/.git/annex/tmp/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b»

    [  <=>                                                                                                                                                                                                 ] 123 245      346K/s   ds 0,3s

2013-09-14 17:24:23 (346 KB/s) - «/srv/video/clips/.git/annex/tmp/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b» sauvegardé [123245]

ok
(Recording state in git...)
anarcat@marcos:clips$ file www.youtube.com_watch_v\=BTzNLhxPzjo
www.youtube.com_watch_v=BTzNLhxPzjo: symbolic link to `.git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b'
anarcat@marcos:clips$ file .git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b
.git/annex/objects/qZ/q1/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b/SHA256E-s123162--96fe8634aaf035373077473ac2b166c5ad22bfe099112c414eee9fe753f4ce2b: HTML document, UTF-8 Unicode text, with very long lines
# End of transcript or log.
"""]]

### Workaround

Use the `quvi` prefix.

> Typo introduced in last release. [[fixed|done]] --[[Joey]]
