Avoid M2Crypto races

As documented in
http://www.heikkitoivonen.net/m2crypto/api/M2Crypto.threading-module.html
and painfully recognized long ago in https://bugzilla.redhat.com/482420,
using M2Crypto in a multi-threaded server such as Vdsm requires explicit
initialization.

Bug-Url: https://bugzilla.redhat.com/1026556
Change-Id: I83a3ab41a7001758bd37b0124904fbcd0387ffbf
Signed-off-by: Dan Kenigsberg <danken@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/20813
Reviewed-by: Juan Hernandez <juan.hernandez@redhat.com>
Reviewed-by: Yaniv Bronhaim <ybronhei@redhat.com>