Fix stop return from gen_statem init

[greg-rychlewski]

When I was testing durations I kept seeing logs like this while running the tests

07:40:52.702 [error] :gen_statem #PID<0.1557.0> terminating
** (stop) {:bad_return_from_init, {:stop, %Postgrex.Error{message: nil, postgres: %{code: :invalid_catalog_name, file: "postinit.c", line: "877", message: "database \"nobody_knows_it\" does not exist", pg_code: "3D000", routine: "InitPostgres", severity: "FATAL", unknown: "FATAL"}, connection_id: nil, query: nil}, %Postgrex.SimpleConnection{idle_interval: 5000, protocol: nil, auto_reconnect: false, reconnect_backoff: 500, state: {Postgrex.Notifications, %Postgrex.Notifications{from: nil, ref: nil, auto_reconnect: false, connected: false, listeners: %{}, listener_channels: %{}}}}}}

Checking the erlang docs it seems like {:stop, reason} should be returned here. The logs don't show up before 1.17 though. I'm guessing due to better error reporting but I'm not 100% sure.

[hauleth]

Could it be released as a patch version to Postgrex?

[josevalim]

v0.19.0 is out.