Postgres add-on optional

[afmicc]

I noticed that the Postgres add-on is automatically added and the DATABASE_URL env var is also set when an app is created using with this buildpack. I don't want to create a new DB for this app, I just want to connect them to an existent one remotely.

I was asking if there would be a way to avoid installing Postgres. Because it's making the app crashes. I tried to set an empty addons array in the app.json file but it didn't work.