fix hookshot missing figma config variable

roles/matrix-bridge-hookshot/templates/config.yml.j2

@@ -73,7 +73,7 @@ generic:
 figma:
   # (Optional) Configure this to enable Figma support
   #
-  publicUrl: https://example.com/hookshot/
+  publicUrl: {{ matrix_hookshot_figma_publicUrl }}
   instances: {{ matrix_hookshot_figma_instances }}
 {% endif %}
 {% if matrix_hookshot_provisioning_enabled %}