#2 Alternative description won't work with comparaison download

[Bertrand FROTTIER]

There's a small problem when downloading a comparaison.
The alternative description is not displayed.
Here is a tiny patch that will fix the problem (a cut
and paste one, I guess...).

You must make sure that the comparaison.php file will
accept both the GET and the POST methods.

[Bertrand FROTTIER]

Bug fix