server: handle unexpected exceptions on connect: `classname` attribute was used on exceptions while it may not exists with some of them. This patch fixes this by showing a warning and re-raising the exception when this case happens.

User-agent: *
Allow: /blog/
Allow: /u/
Allow: /b/
Disallow: /libervia.html
Disallow: /mr
Disallow: /login

User-agent: Mediapartners-*
Disallow: /