develop bug: SLC buffer wrong size: expect multiple of 3

[jquast]

2016-04-05 17:48:55,653 INFO server_base.py:124 Connection from <Peer 173.227.7.2 50188>
2016-04-05 17:48:55,655 WARNING stream_writer.py:1383 Unhandled: WILL AUTHENTICATION.
2016-04-05 17:48:56,013 WARNING server_base.py:298 File "/home/dingo/telnetlib3/telnetlib3/server_base.py", line 149, in data_received
2016-04-05 17:48:56,013 WARNING server_base.py:298 recv_inband = self.writer.feed_byte(bytes([byte]))
2016-04-05 17:48:56,013 WARNING server_base.py:298 File "/home/dingo/telnetlib3/telnetlib3/stream_writer.py", line 275, in feed_byte
2016-04-05 17:48:56,013 WARNING server_base.py:298 self.handle_subnegotiation(self._sb_buffer)
2016-04-05 17:48:56,013 WARNING server_base.py:298 File "/home/dingo/telnetlib3/telnetlib3/stream_writer.py", line 1436, in handle_subnegotiatio
n
2016-04-05 17:48:56,014 WARNING server_base.py:298 self._handle_sb_linemode(buf)
2016-04-05 17:48:56,014 WARNING server_base.py:298 File "/home/dingo/telnetlib3/telnetlib3/stream_writer.py", line 1876, in _handle_sb_linemode
2016-04-05 17:48:56,014 WARNING server_base.py:298 self._handle_sb_linemode_slc(buf)
2016-04-05 17:48:56,014 WARNING server_base.py:298 File "/home/dingo/telnetlib3/telnetlib3/stream_writer.py", line 1957, in handle_sb_linemode
slc
2016-04-05 17:48:56,014 WARNING server_base.py:298 raise ValueError('SLC buffer wrong size: expect multiple of 3')
2016-04-05 17:48:56,014 WARNING server_base.py:298 ValueError: SLC buffer wrong size: expect multiple of 3