Support for OpenSSL 1.1.0:

- SRP_VBASE_get_by_user() is deprecated now,
  one should use SRP_VBASE_get1_by_user()
  instead. The new function returns a pointer
  owned by the callee. It must be freed after
  use.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1735877 13f79535-47bb-0310-9956-ffa450edef68