Zabbix

A......... [ZBX-24481] fixed inability to unset value map from existing item or item prototype by passing a version without valuemap parameter into configuration.import

* commit '1ef9c15925ae784dc3e6ec303062702f49186f2f':
  A......... [ZBX-24481] fixed inability to unset value map from existing item or item prototype by passing version without valuemap parameter into configuration.import