mod_ssl: Fix merging of proxy SSL context outside <Proxy> sections.

Regression introduced in 2.4.30. PR 62232.

The proxy SSL_CTX was not inherited from the vhost (the only available in
2.4.29) in/for any directory context besides <Proxy>...

Mostly debugged and fixed by Rainer, thanks!


Submitted by: ylavic
Reviewed by: ylavic, rpluem, jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1828735 13f79535-47bb-0310-9956-ffa450edef68