Nenhuma opção na tela "Erro de privacidade"
Não é algo que você possa anular. A tela de erro do Firefox é um pouco mais informativa:
The owner of feedback.appharbor.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.
This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate.
...
feedback.appharbor.com uses an invalid security certificate. The certificate is only valid for the following names: ssl149278.cloudflaressl.com, *.uservoice.com, uservoice.com Error code: SSL_ERROR_BAD_CERT_DOMAIN
Sugiro que você envie um email para [email protected] ou [email protected] para relatar o erro.