Merge r1679470 from trunk:

mod_ssl: follow up to r1527291.
Always prepend "!aNULL:!eNULL:" to SSL_DEFAULT_CIPHER_LIST (default for
SSL[Proxy]CipherSuite) since we support OpenSSL versions where this was
not yet included by default.

Submitted by: ylavic
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1679989 13f79535-47bb-0310-9956-ffa450edef68