Agnostic baker manual command issue

Problem described in Slack thread:

./octez-baker-PsQuebec

gives the manual, but

./octez-agnostic-baker 
Apr 07 15:22:32.193: experimental agnostic baker started
Apr 07 15:22:32.193: [WARNING] As the name suggests, this binary is EXPERIMENTAL, therefore it is intended for testing purposes only. Please do not use it on
Apr 07 15:22:32.193:   `mainnet`.
Error:
  Cannot connect to node. Connection refused (ECONNREFUSED): http://localhost:8732

This should follow the logic from !17410 (merged)