* remove web3 url prompt in launcher script
The interactive prompt for web3 has outlived its utility as we now load
url:s from command line params and config files, preventing the prompt
from correctly detecting when it's needed.
Also, after the merge, a JWT secret will (likely) be needed.
* log notice when web3 url is missing
* fix docs to not mention default that doesn't exist
* fix scripts to properly quote arguments