[Tails-dev] [review] fix link

Hi,

Please review (and maybe merge):
https://gitorious.org/flapflap/tailsxlat.git
branch wiki-fix-fullstop

Commits:
36001f1 fix '.' in URL

In a link on the doc/about/warning.mdwn page, there was a double '.' at
the end of a sentence. It's not part of the title of the referenced
webpage and (I think :-) it looks unaesthetic..

I fixed it in the mdwn version /and de-fr-pt translations/.

~flapflap