Upload via TCP and restart results in ugly python exception

[eku]

Many thanks for adding upload via TCP. Unfortunately a triggered restart of the NodeMCU will cause the script to hang until the module is online again and then throw an exception.

->node.restart()Traceback (most recent call last):
  File "./luatool.py", line 310, in <module>
    transport.writeln("node.restart()\r")
  File "./luatool.py", line 147, in writeln
    self.performcheck(data)
  File "./luatool.py", line 59, in performcheck
    char = self.read(1)
  File "./luatool.py", line 152, in read
    return self.socket.recv(length)
socket.error: [Errno 104] Connection reset by peer