fix: import webapp.config at the top of app module

Author: edisile

webapp/app.py

@@ -10,6 +10,7 @@
 from talisker import logging
 
 from canonicalwebteam.flask_base.app import FlaskBase
+import webapp.config
 from webapp.blog.views import init_blog
 from webapp.docs.views import init_docs
 from webapp.extensions import csrf