Fixed urllib exeptions import after update requests to 2.6.0-8.el7_7

[k0ste]

Traceback (most recent call last):
File "/usr/lib/zabbix/alertscripts/zbxtg.py", line 939, in <module>
main()
File "/usr/lib/zabbix/alertscripts/zbxtg.py", line 884, in main
zbx.login()
File "/usr/lib/zabbix/alertscripts/zbxtg.py", line 291, in login
requests.packages.urllib3.disable_warnings()
AttributeError: 'module' object has no attribute 'urllib3'