Remove matrix_s3 references from matrix-dendrite role

All the `matrix_s3_*` stuff happens in the `matrix-synapse` role.

If we are to have such S3 support for Dendrite, we should probably
extract it out of the `matrix-synapse` role (into a `matrix-s3` role or
`matrix-goofys`, etc.) and wire `matrix-dendrite` accordingly.

This may or may not be done in the future though. For now, I'm
cleaning things up in the `matrix-dendrite` role.

roles/matrix-dendrite/tasks/init.yml

@@ -1,7 +1,3 @@
 - set_fact:
     matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-dendrite.service'] }}"
   when: matrix_dendrite_enabled|bool
-
-- set_fact:
-    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-goofys.service'] }}"
-  when: matrix_s3_media_store_enabled|bool