OpenSSl 1.1.0 support

- improve renegotiation loop.
  Should now also work in case only the
  cipher changes.
  Should now also work in case the handshake
  ends with an error.

Backport of r1729498 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x-openssl-1.1.0-compat@1755824 13f79535-47bb-0310-9956-ffa450edef68