[QA] Recomend an SSL connection with the databases

[jnweiger]

WHAT Needs to be Documented?

The admin should be made aware of SSL connections to the database

WHERE Does This Need To Be Documented (Link)?

https://github.com/owncloud/docs/blob/master/modules/admin_manual/pages/configuration/database/linux_database_configuration.adoc

WHY Should This Change Be Made?

When the database is remote, SSL is more secure.

(Optional) What Type Of Content Change Is This?

• [x] New Content Addition

(Optional) Which Manual Does This Relate To?

• [x] Admin Manual