Original whining and use case is buried in the comments to CVE fix announcement. In summary: http_proxy environment variable could point to some address within local network (e.g. security.allowed-ip-addresses (or older annex.security.allowed-http-addresses) seems to support only a whitespace separate list of addresses (too tedious to list for sizeable private networks) or "all" (too much) not support networks.
In case of http_proxy it would also be valuable to be able to limit to specific (e.g. privileged) port(s) (thus kicking back to http from a generic ip), to avoid opening access to some malicious user providing URLs on the same private network on some other port. I think both address + port "wishlist" items are related thus filing in a single issue.