Updated var names

roles/matrix-synapse/tasks/synapse/setup_install.yml

@@ -130,7 +130,7 @@
     mode: 0755
 
 - set_fact:
-    matrix_synapse_media_storage_providers: |
+    media_storage_providers: |
       {{
         matrix_synapse_media_storage_providers|default([])
         +

roles/matrix-synapse/templates/synapse/homeserver.yaml.j2

@@ -1039,7 +1039,9 @@ media_store_path: "/matrix-media-store-parent/{{ matrix_synapse_media_store_dire
 #    config:
 #       directory: /mnt/some/other/directory
 
+{% if matrix_synapse_media_storage_provider_s3_enabled %}
 media_storage_providers: {{ matrix_synapse_media_storage_providers|to_json }}
+{% endif %}
 
 # The largest allowed upload size in bytes
 #