`matrix_synapse_no_tls` is now implicit, so we've gotten rid of it.

The `homeserver.yaml.j2` template has been synchronized with the
configuration generated by Synapse v0.99.1 (some new options
are present, etc.)

We had something like that on the Server Delegation how-to page,
but it's better if we have it on the SSL certificates page.

Relocated there and improved linking.

Fixes #94 (Github Issue)