Phoenix uses wrong port

Hi,

I created a new Phoenix umbrella application. I am trying to configure it to use different port, but the port does not change.

$ mix phx.new test --umbrella --no-ecto

In test_umbrella/config/prod.exs:

I uncommented this line:

config :test_web, TestWeb.Endpoint, server: true

and configured the ip and the port:

config :test_web, TestWeb.Endpoint,
  url: [ip: [0,0,0,0], port: 1234],
  cache_static_manifest: "priv/static/cache_manifest.json"

Then I ran:

$ cd test_umbrella/
$ SECRET_KEY_BASE=$(mix phx.gen.secret) MIX_ENV=prod mix phx.server

The server starts, but cowboy listens on port 4000 instead of 1234.

08:14:34.496 [info] Running TestWeb.Endpoint with cowboy 2.6.3 at :::4000 (http)
08:14:34.498 [info] Access TestWeb.Endpoint at http://localhost:1234
08:15:13.928 request_id=Fa1_NZgFyPdDboEAACYH [info] GET /
08:15:13.929 request_id=Fa1_NZgFyPdDboEAACYH [info] Sent 200 in 1ms

$ curl 0.0.0.0:1234
curl: (7) Failed to connect to 0.0.0.0 port 1234: Connection refused
$ curl 127.0.0.1:1234
curl: (7) Failed to connect to 127.0.0.1 port 1234: Connection refused
$ curl 0.0.0.0:4000
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8"/>
[...]

Some additional information:

$ elixir --version
Erlang/OTP 22 [erts-10.4.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe] [dtrace]
Elixir 1.9.0 (compiled with Erlang/OTP 22)

$ mix phx.new --version
Phoenix v1.4.8

$ uname -a
Darwin MBPro.local 18.6.0 Darwin Kernel Version 18.6.0: Thu Apr 25 23:16:27 PDT 2019; root:xnu- 
4903.261.4~2/RELEASE_X86_64 x86_64