tls: increase Diffie-Hellman group size to 2048 bits
1024 bits is already the minimum accepted size of current TLS libraries. 2048
is recommended for servers, see https://weakdh.org/
BUG: https://bugzilla.samba.org/show_bug.cgi?id=11804
Signed-off-by: Bjoern Jacke <bj@sernet.de>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Thu Sep 3 03:47:48 CEST 2015 on sn-devel-104
(cherry picked from commit
22a37c453d83c39634fbae72de592024d9b8ba4a)