[gitosis] unexpected error for a warning msg

Hi,

I had the following issue using gitosis today:
http://colabti.org/irclogger/irclogger_log/git?date=2009-05-03#l2233

The name of the key file was 'keydir/Jacques@BLACK_ANTEC.pub' which gave
the warning (when pushing): 
WARNING:gitosis.ssh:Unsafe SSH username in keyfile: Jacques@BLACK_ANTEC.pub

Changing the filename into Jacques.pub solved the issue.

I was expecting an error message instead (not a warning) as it seems to
_not_ permit such a filename.

Why the initial filename is fobidden?
Could the warning be substituted by an error?

Thanks,

-- 
Nicolas Sebrecht