make readings safe

Author: bnmnetp

runestone/common/project_template/_templates/plugin_layouts/sphinx_bootstrap/layout.html

@@ -243,7 +243,7 @@
     eBookConfig.email = '{{ user_email }}';
     eBookConfig.isInstructor = {{ is_instructor }};
     eBookConfig.username = '{{ user_id}}';
-    eBookConfig.readings = {{ readings}};
+    eBookConfig.readings = {{ readings|safe}};
     eBookConfig.activities = {{ activity_info|safe }}
     eBookConfig.downloadsEnabled = {{downloads_enabled}};
     eBookConfig.allow_pairs = {{allow_pairs}}