Steps to reproduce:

1. use "zabbix_get -s 127.0.0.1 -p 10050 -k web.certificate.get[example.com]"
2. not working, because http_proxy variable is missing

Result: It is neccessary to implement a new variable for "http_proxy" in the following script: https://github.com/zabbix/zabbix/blob/master/src/zabbix_get/zabbix_get.c