matrix: enable URL previews

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

@@ -983,7 +983,7 @@ max_upload_size: 25M
 # 'false' by default: uncomment the following to enable it (and specify a
 # url_preview_ip_range_blacklist blacklist).
 #
-#url_preview_enabled: true
+url_preview_enabled: true
 
 # List of IP address CIDR ranges that the URL preview spider is denied
 # from accessing.  There are no defaults: you must explicitly
@@ -1001,26 +1001,26 @@ max_upload_size: 25M
 #
 # Note: The value is ignored when an HTTP proxy is in use
 #
-#url_preview_ip_range_blacklist:
-#  - '127.0.0.0/8'
-#  - '10.0.0.0/8'
-#  - '172.16.0.0/12'
-#  - '192.168.0.0/16'
-#  - '100.64.0.0/10'
-#  - '192.0.0.0/24'
-#  - '169.254.0.0/16'
-#  - '192.88.99.0/24'
-#  - '198.18.0.0/15'
-#  - '192.0.2.0/24'
-#  - '198.51.100.0/24'
-#  - '203.0.113.0/24'
-#  - '224.0.0.0/4'
-#  - '::1/128'
-#  - 'fe80::/10'
-#  - 'fc00::/7'
-#  - '2001:db8::/32'
-#  - 'ff00::/8'
-#  - 'fec0::/10'
+url_preview_ip_range_blacklist:
+  - '127.0.0.0/8'
+  - '10.0.0.0/8'
+  - '172.16.0.0/12'
+  - '192.168.0.0/16'
+  - '100.64.0.0/10'
+  - '192.0.0.0/24'
+  - '169.254.0.0/16'
+  - '192.88.99.0/24'
+  - '198.18.0.0/15'
+  - '192.0.2.0/24'
+  - '198.51.100.0/24'
+  - '203.0.113.0/24'
+  - '224.0.0.0/4'
+  - '::1/128'
+  - 'fe80::/10'
+  - 'fc00::/7'
+  - '2001:db8::/32'
+  - 'ff00::/8'
+  - 'fec0::/10'
 
 # List of IP address CIDR ranges that the URL preview spider is allowed
 # to access even if they are specified in url_preview_ip_range_blacklist.