mailman: SSL settings to Apache 2.4 and "mid"
Changes the SSL settings for lists/mailman to Apache 2.4
and the "mid" option for the ciphers list, when on jessie or greater.
- mid: Supports TLSv1.0 and higher, and adds several forward-secret options which are not AEAD. This is compatible with many more clients than "strong". With a DHE-capable server, should only be incompatible with IE8/XP, ancient/un-updated Java6, and some small corner cases like Nokia feature phones. With a non-DHE server, compatibility is also lost with Android 2.x, OpenSSL 0.9.8, and more Java6 clients.
- compat: Supports most legacy clients, PFS optional but preferred.
Can only be merged after lists is off of sodium and on fermium.