Dojo with exposed bitcoind ports doesn't start (linux)

[LaurentMT]

Reproduced on OS: Linux & Windows
Reproduced on Dojo:: v1.1 & develop

Steps to reproduce the issue

- stop dojo

- edit docker-bitcoind.conf and set
BITCOIND_RPC_EXTERNAL=on
BITCOIND_RPC_EXTERNAL_IP=127.0.0.1

- start dojo

Error

WARNING: The BITCOIND_RPC_EXTERNAL_IP variable is not set. Defaulting to a blank string.
ERROR: The Compose file '/home/ubuntu/API-Server-refactoring-node8/docker/my-dojo/overrides/bitcoind.rpc.expose.yaml' is invalid because:
services.bitcoind.ports contains an invalid type, it should be a number, or an object
services.bitcoind.ports contains an invalid type, it should be a number, or an object
services.bitcoind.ports contains an invalid type, it should be a number, or an object
services.bitcoind.ports contains an invalid type, it should be a number, or an object
services.bitcoind.ports contains an invalid type, it should be a number, or an object