Zabbix Discovery rule by check Telnet 10050

[Yaohua]

Hi,I want to discovery some hosts by check telnet 10050.
but the zabbix-server.log output as following
```
3413:20170720:105305.646 In telnet_waitsocket()
3413:20170720:105305.747 End of telnet_waitsocket():0
3413:20170720:105305.747 End of telnet_socket_read():0
3413:20170720:105305.747 End of telnet_read():0
3413:20170720:105305.747 In telnet_read()
3413:20170720:105305.747 In telnet_socket_read()
3413:20170720:105305.747 telnet_socket_read() rc:-1 errno:11 error:[[11] Resource temporarily unavailable]
3413:20170720:105305.747 In telnet_waitsocket()
```
so what should i do?