chore(Conn): move Validate below ProxyHeaderPolicy

This field order reflect usage pattern and avoids mixing exported and unexported fields.

protocol.go

@@ -43,10 +43,10 @@ type Conn struct {
  once sync.Once
  readErr error
  conn net.Conn
- Validate Validator
  bufReader *bufio.Reader
  header *Header
  ProxyHeaderPolicy Policy
+ Validate Validator
  readHeaderTimeout time.Duration
 }