`starport c serve` doesn't use `init.client.keyring-backend`

[fadeev]

Describe the bug
starport c serve doesn't use init.client.keyring-backend

To Reproduce

starport s chain github.com/cosmosnaut/mars

Set the keyring backend to os in config.yml:

init:
  client:
    keyring-backend: os

starport c serve

Please provide output of commands

• starport version: starport version development darwin/amd64 -build date: 2021-08-09T15:37:14
  git object hash: 2872f6c

[fadeev]

Done!