Had the same issue. Patch above didn't work.
This lin added to /etc/uwsgi/apps-available/graphite.ini did it, though:
pymodule-alias = graphite.local_settings=/etc/graphite/local_settings.py
and set ownership of /etc/graphite/local_settings.py to _graphite:_graphite
(going with the 0400 permissions set in #882691.
Thank you,
Gerardo

