zones: Env: allow multiple gateways on a Zone

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/zones/env.go

@@ -65,11 +65,16 @@ func (m *Env) writeEnvVarInts(w io.Writer, value []int, name string, args ...any
 	var s string
 
 	if n := len(value); n > 0 {
-		ss := make([]string, len(value))
+		var buf bytes.Buffer
+
 		for i, v := range value {
-			ss[i] = fmt.Sprintf("%v", v)
+			if i != 0 {
+				_, _ = fmt.Fprint(&buf, " ")
+			}
+			_, _ = fmt.Fprintf(&buf, "%v", v)
 		}
-		s = strings.Join(ss, " ")
+
+		s = buf.String()
 	}
 
 	m.writeEnvVar(w, s, name, args...)