Done via the following command:
git diff 1e6c102b --stat --name-only | cat - | xargs sed -i 's/2017-2018 Pleroma Authors/2017-2019 Pleroma Authors/'

instead of cwd and load the application before doing anything

In OTP releases cwd != app directory and the configuration is read
only if the application is loaded

ecto.migrate
ecto.rollback