I needed this change in order to read config files

We didn't need this previously, so I'm a little concerned by it.
Tweaked as part of DEVOPS-5543

playbooks/edx-east/populate_configuration_model.yml

@@ -36,6 +36,8 @@
   vars:
     python_path: /edx/bin/python.edxapp
     manage_path: /edx/bin/manage.edxapp
+  become_user: www-data
+  become: true
   tasks:
     - name: Create a temp directory
       shell: mktemp -d /tmp/ansible_xblock_config.XXXXX