mod_proxy with sqlite vs selinux

Something to add to the documentation:

if sestatus is enforcing you need to make sure proftpd may write to the ProxyTables path.

with e.g.:
```
ProxyTables /var/ftp/proxy
```
then:
```sh
semanage fcontext --add --type public_content_rw_t '/var/ftp/proxy(/.*)?'
setsebool -P ftpd_anon_write=1
```
will make it all better. There may be better selinux types to use, of course.