Backports: r892678

Submitted by: niq
Reject requests containing (invalid) NULL characters in request line
or request headers.
PR 43039

Backports: r892808
Submitted by: rpluem
Fix up r892678


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x-merge-http-strict@1775731 13f79535-47bb-0310-9956-ffa450edef68