Fix getting stuck in loop in socket_listen

If `socket_listen` was called, and a connection was made right
away, it was possible that the state of the socket would change
to `SNSR_SOCK_ESTABLISHED` before the check ever saw it enter
`SNSR_SOCK_LISTEN`, and the code would be stuck in an endless
loop.

This fixes the issue by accepting both `SNSR_SOCK_LISTEN` and
`SNSR_SOCK_ESTABLISHED` as valid states to continue.

Author: xorbit

adafruit_wiznet5k/adafruit_wiznet5k.py

@@ -563,7 +563,7 @@ def socket_listen(self, socket_num, port):
         self._send_socket_cmd(socket_num, CMD_SOCK_LISTEN)
         # Wait until ready
         status = [SNSR_SOCK_CLOSED]
-        while status[0] != SNSR_SOCK_LISTEN:
+        while status[0] not in (SNSR_SOCK_LISTEN, SNSR_SOCK_ESTABLISHED):
             status = self._read_snsr(socket_num)
             if status[0] == SNSR_SOCK_CLOSED:
                 raise RuntimeError("Listening socket closed.")