Potential corruption in EncryptedMessage.transferTo

`EncryptedMessage.transferTo` has a potential corruption issue. When the underlying buffer has more than `1024 * 32` bytes (this should be rare but it could happen in error messages that send over the wire), it may just send a partial message as `EncryptedMessage.count` becomes less than `transferred`. This will cause the client hang forever (or timeout) as it will wait until receiving expected length of bytes, or weird errors (such as corruption or silent correctness issue) if the channel is reused by other messages.