Pidgin should rely on the cached certificates
Originally created by Tails on #5909 (Redmine)
In Tails 0.19, the certificate shipped for jabber.ccc.de has expired. Pidgin silently uses it and replaces it with the new one in the cache.
It is still the case in Jessie (as tested), we should report and correct it.
- Related to #7730 (closed)