remove unused empty variables

templates/opt/matrix/config/homeserver.yml.j2

@@ -9,7 +9,7 @@ pid_file: /var/run/homeserver.pid
 
 # The path to the web client which will be served at /_matrix/client/
 # if 'webclient' is configured under the 'listeners' configuration.
-web_client_location: "{{ matrix_web_client_location }}"
+# web_client_location: "{{ matrix_web_client_location }}"
 
 # The public-facing base URL that clients use to access this HS
 public_baseurl: "{{ matrix_client_url }}"
@@ -163,7 +163,7 @@ federation_client_minimum_tls_version: 1.2
 
 # Skip federation certificate verification on the following whitelist
 # of domains.
-federation_certificate_verification_whitelist: []
+# federation_certificate_verification_whitelist: []
 {% endif %}
 
 ## Database ##