Add a clear OpenSSL exception.
    
    We are linking with OpenSSL in 2 files, so make it clear we intentionally
    add a GPLv3 exception to allow that linking by third parties.
    
    Signed-off-by: Simo Sorce <simo@redhat.com>
    Reviewed-By: Nathaniel McCallum <npmccallum@redhat.com>