Fix the naming of the apr_threadattr_detach_xxx functions. get and set were

reversed.

This may have broken the Unix threaded mpm's when they started using the
bogus "set" function.  A likely symptom would be failure to stop a threaded
process cleanly.

Note: it appears these functions are essentially no-ops except in Unix.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88805 13f79535-47bb-0310-9956-ffa450edef68