Add missing quotes

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2089

group_vars/matrix_servers

@@ -1354,7 +1354,7 @@ matrix_cactus_comments_systemd_required_services_list: |
     (['matrix-' + matrix_homeserver_implementation + '.service'])
   }}
 
-matrix_cactus_comments_client_nginx_path: {{ '/cactus-comments/' if matrix_nginx_proxy_enabled else matrix_cactus_comments_client_path + '/' }}
+matrix_cactus_comments_client_nginx_path: "{{ '/cactus-comments/' if matrix_nginx_proxy_enabled else matrix_cactus_comments_client_path + '/' }}"
 
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