fix for the apache::mod::python manifest

Hi,

The python.conf created by the manifest apache::mod::python was being deleted by the purging of the httpd_vdir directory. 
This fix guarantees the permance of the file python.conf during the execution of the purge of the directory httpd_vdir.
It's similiar to the fix  in the apache::mod::php manifest.

Best regards,
Vitor