Fix regexp in access_wrapper
Fix regexp in access_wrapper

The `to` field to catch the `what` part for the acl must be forced at
word boundary. Otherway, an expression like `to attrs=jpegphoto
filter=...` the catched `to` is the final part of `jpegphoto`, not the
wanted `to`.

nfrance-conseil/puppet-openldap,camptocamp/puppet-openldap