Finish fixing the pcre build. PCRE's configure script should be called,

and we can't clean config.h and then touch the file, we actually need
some of the data that config.h contains.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86132 13f79535-47bb-0310-9956-ffa450edef68