fix(libs/utils): Use valid ip4 address (#2394)

Fixes an issue where `localhost` was not accepted as a valid
`--gateway.addr`. Uses net.ResolveIPAddr instead.

Found by @tuxcanfly

libs/utils/address.go

@@ -29,15 +29,14 @@ func ValidateAddr(addr string) (string, error) {
  return addr, err
  }
 
- if ip := net.ParseIP(addr); ip == nil {
- addrs, err := net.LookupHost(addr)
- if err != nil {
- return addr, fmt.Errorf("could not resolve %v: %w", addr, err)
- }
- if len(addrs) == 0 {
- return addr, fmt.Errorf("no IP addresses found for DNS record: %v", addr)
- }
- addr = addrs[0]
+ ip := net.ParseIP(addr)
+ if ip != nil {
+ return addr, nil
  }
- return addr, nil
+
+ resolved, err := net.ResolveIPAddr("ip4", addr)
+ if err != nil {
+ return addr, err
+ }
+ return resolved.String(), nil
 }