🐞 ;; Warning: ID mismatch: expected ID x, got y

When I ran the following code, I would get at least one of the above
messages when run on the Linux CI container:

```bash
for i in $(seq 1 32); do
  dig @localhost asdf +short &
done
```

The error hasn't recurred after this change, in spite of running the
above code a dozen times.

bosh-release/src/sslip.io-dns-server/main.go

@@ -13,9 +13,8 @@ func main() {
 		log.Fatal(err.Error())
 	}
 
-	query := make([]byte, 512)
-
 	for {
+		query := make([]byte, 512)
 		_, addr, err := conn.ReadFromUDP(query)
 		if err != nil {
 			log.Println(err.Error())