Zabbix

...G...... [ZBX-19267] moved check for empty property value after check if property is "key"

Merge in ZBX/zabbix from feature/ZBX-19267-7.0 to release/7.0

* commit 'd060db1b5d44f4b244b9cb78311270d7ae0a5c4c':
  ...G...... [ZBX-19267] added comments and fixed ChangeLog entry
  ...G...... [ZBX-19267] reworked code following guidelines
  ...G...... [ZBX-19267] moved check for empty property value after check if property is "key"

(cherry picked from commit 9bf00d9a5334f9b02ff803e507b972556737369d)
(cherry picked from commit 7d867a3719ac3426560bcb65d23b25800c0571a9)
(cherry picked from commit ee31798d42165d56992faee07692076e91ae0510)