Attached patch fixes the compilation with httpd-2.4 and should fulfil https://fedoraproject.org/wiki/PackagingDrafts/ApacheHTTPModules draft. I've tested it briefly (just set the download speed on localhost to 10kbps), tested the download and checked the cband-status). You should check it yourself before using the patch and send the patch upstream too.
Created attachment 575315 [details] proposed patch
This one seems to be retired in the pkgdb but not in git. I've completed the EOL process for this one to finish it off.