Update notify_operator.py

[fgenellini]

According https://github.com/pistolero/zbxsend syntax, the function is not wearing a zbxsend third parameter after the port. In my case, I had to remove the "20" at the end of the line No. 141 to work with Zabbix sender.

[paleg]

You are probably using old version of zbxsend (<0.1.5).
Recent versions of send_to_zabbix accepts 4 parameters.
https://github.com/pistolero/zbxsend/blob/master/zbxsend.py#L23

[fgenellini]

@paleg
I installed it with pip (zbx_send 1.6) (https://pypi.python.org/pypi/zbxsend/0.1.6) and to work with Zabbix 2.4 had to take the third parameter. Finally, seeing the code you are right, but I have not cleansed from end to end.