Merge branch 'setting-frontend-version' into 'master'

Avoid empty FRONTEND_VERSION with the new config style

See merge request !752

arkindex/project/settings.py

@@ -167,7 +167,7 @@ STATIC_ROOT = conf['static']['root_path']
 STATICFILES_DIRS = []
 
 # By default the frontend version is the same as the backend
-FRONTEND_VERSION = conf['static'].get('frontend_version', VERSION)
+FRONTEND_VERSION = conf['static'].get('frontend_version') or VERSION
 
 # API
 REST_FRAMEWORK = {