mailing list: change to the newly set up one

The Mailman instance at lists.i2p2.(de|i2p) was set up by Meeh and I in 2013
and is accessible via both I2P and the internet with newly set-up SSL certs.

i2p2www/templatevars.py

@@ -9,6 +9,7 @@ I2P_TO_CLEAR = {
     'forum.i2p': 'forum.i2p', # Don't convert forum.i2p, it is not accessible outside I2P
     'trac.i2p2.i2p': 'trac.i2p2.de',
     'mail.i2p': 'i2pmail.org',
+    'lists.i2p2.i2p': 'lists.i2p2.de',
     }