update sample config

matrix.yml

@@ -49,4 +49,6 @@
       update_cache: yes
   - template:
       src: templates/homeserver.yaml.j2
-      dest: /etc/matrix-synapse/homeserver.yaml
+      dest: /etc/matrix-synapse/homeserver.yaml
+  vars:
+  - matrix_server_name: matrix.fuz.re

server_name.yaml

@@ -1,9 +0,0 @@
-# This file is autogenerated, and will be recreated on upgrade if it is deleted.
-# Any changes you make will be preserved.
-
-# The domain name of the server, with optional explicit port.
-# This is used by remote servers to connect to this server,
-# e.g. matrix.org, localhost:8080, etc.
-# This is also the last part of your UserID.
-#
-server_name: matrix.fuz.re