`--allow-net` flag is impossible to set with env?

[fracek]

Describe the bug

I want to set the --allow-net flag from environment (e.g. in a container), but setting ALLOW_NET="" results in an empty hostname.

To Reproduce

• create an indexer script that matches a network call, e.g. fetch("https://google.com")
• run the indexer with --allow-net, it should work
• remove the --allow-net flag, use export ALLOW_NET=""
• run the indexer again, it fails with an error about an empty host

Expected behavior

The indexer should interpret an empty string as an empty list of hosts.

Additional context

Add any other context about the problem here.