Add blobs options to Soledad Server configuration template

Soledad now provides a blobs service with a mail delivery api, and some configuration options have to be added to the soledad server configuration template in the platform.

The configuration options that have to be added are:

option	default value
blobs	false
blobs_path	/var/lib/soledad/blobs
services_tokens_file	/etc/soledad/services.tokens