RtmpUint16 UnmarshalBinary incorrect byteorder

[avfedorov]

Byteorder in protocol.RtmpUint16 UnmarshalBinary is incorrect.
Current:
*v = RtmpUint16(uint16(data[0]) | uint16(data[1])<<8)
Must be:
*v = RtmpUint16(uint16(data[1]) | uint16(data[0])<<8)

This leads to an incorrect decoding of UserControlMessage for example.

[winlinvip]

Thanks， I will check it.