main core: Emit errors during the initial apr_app_initialize()

or apr_pool_create() (when apr-based error reporting is not ready).
[William Rowe, Jeff Trawick]

Backport: 568779, 569934


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@570309 13f79535-47bb-0310-9956-ffa450edef68