don't log packet on decryption error

since that is expensive and clutters the logs

router/crypto.go

@@ -371,7 +371,7 @@ func (nd *NaClDecryptor) decrypt(buf []byte) ([]byte, error) {
 		usedOffsets.Add(offsetNoFlagsInt)
 		return result, nil
 	} else {
-		return nil, fmt.Errorf("Unable to decrypt msg via UDP: %v", buf)
+		return nil, fmt.Errorf("Unable to decrypt UDP packet")
 	}
 }
 
@@ -436,7 +436,7 @@ func NewEncryptedTCPReceiver(conn *LocalConnection) *EncryptedTCPReceiver {
 func (receiver *EncryptedTCPReceiver) Decode(msg []byte) ([]byte, error) {
 	plaintext, success := DecryptPrefixNonce(msg, receiver.conn.SessionKey)
 	if !success {
-		return msg, fmt.Errorf("Unable to decrypt msg via TCP:\n %X", msg)
+		return msg, fmt.Errorf("Unable to decrypt TCP msg")
 	}
 	receiver.buffer.Reset()
 	_, err := receiver.buffer.Write(plaintext)