[Fix] shrinks window before connecting (#905)

Close #821

For further details please see:
- https://lore.kernel.org/all/20231103092706.6rw2ehuigxfdvhlc@lion.mk-sys.cz/
- https://bugzilla.suse.com/show_bug.cgi?id=1216858
- #821

tests/greenio_test.py

@@ -417,8 +417,8 @@ def server():
 
         server_evt = eventlet.spawn(server)
         client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        client.connect(('127.0.0.1', listener.getsockname()[1]))
         bufsized(client)
+        client.connect(('127.0.0.1', listener.getsockname()[1]))
         large_evt = eventlet.spawn(read_large, client)
         eventlet.sleep(0)
         client.sendall(b'hello world')