Part of a fix for not being able to reset the --prefix. This will

allow the installation prefix to be reset after a "make clean". To do
this really properly, all the code that depends on the prefix should
have a dependency in the makefile. This is coming RSN.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@84719 13f79535-47bb-0310-9956-ffa450edef68