Gateway testing bug fix
Created by: VoidingWarranties
There was a bug in testing that prevented an RPC from calling another RPC. This was because a gateway would connect to a peer with the address "[::]:port" (the unspecified IPV6 address), but during the RPC the conn
would have the remote address "[::1]:port" (the localhost IPV6 address). The fix is to use "localhost:0" instead of ":0".
This bug only affected tests and the only files changed in this PR are test files.