Turn 5.1/5.2 order upside down, simplify. This should also (AFAIK) work with...

Turn 5.1/5.2 order upside down, simplify. This should also (AFAIK) work with Ubuntu/Debian, which has previously been known to fail to compile mod_lua.so

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1706533 13f79535-47bb-0310-9956-ffa450edef68