fix template error

defaults/main.yml

@@ -113,22 +113,22 @@ matrix_url_preview_enabled: False
 # anyone in any Matrix room could cause your synapse to issue arbitrary
 # GET requests to your internal services, causing serious security issues.
 # matrix_url_preview_blacklist: # defaults to not set
-#   - '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'
-#   - '169.254.0.0/16'
-#   - '::1/128'
-#   - 'fe80::/64'
-#   - 'fc00::/7'
+#   - "'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'"
+#   - "'169.254.0.0/16'"
+#   - "'::1/128'"
+#   - "'fe80::/64'"
+#   - "'fc00::/7'"
 
 # Optional list of URL matches that the URL preview spider is
 # denied from accessing.
 # https://docs.python.org/2/library/urlparse.html#urlparse.urlsplit
 # matrix_url_preview_url_blacklist:
-#   - netloc: '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'
-#   - netloc: '^([A-f0-9:]+:+)+[A-f0-9]+$'
+#   - netloc: "'^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'"
+#   - netloc: "'^([A-f0-9:]+:+)+[A-f0-9]+$'"
 matrix_url_preview_max_spider_size: 10M
 
 matrix_tls_enabled: False

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

@@ -320,11 +320,11 @@ thumbnail_sizes:
 # Is the preview URL API enabled?  If enabled, you *must* specify
 # an explicit url_preview_ip_range_blacklist of IPs that the spider is
 # denied from accessing.
-url_preview_enabled: {% 'True' if matrix_url_preview_enabled else 'False' %}
+url_preview_enabled: {{ 'True' if matrix_url_preview_enabled else 'False' }}
 
 {% if matrix_url_preview_ip_blacklist is defined %}
 url_preview_ip_range_blacklist:
-{{ matrix_url_preview_ip_blacklist | to_nice_yaml(indent=8) }}
+{{ matrix_url_preview_ip_blacklist | to_nice_yaml(indent=2) }}
 {% endif %}
 
 # List of IP address CIDR ranges that the URL preview spider is allowed