Zabbix

.......... [DEV-2614] fixed stack-buffer overflow in library module zbxjson

Merge in ZBX/zabbix from feature/DEV-2614-6.4 to release/6.4

* commit '3015f7cc312c2b02e8006d723ee946a96ec27ed6':
  .......... [DEV-2614] fixed PR warnings and cmocka tests
  .......... [DEV-2614] fixed stack-buffer overflow in library module zbxjson

(cherry picked from commit c86ea061d43aaf91ad2f5f82fbc90ad668921076)