Zabbix

........S. [ZBX-21510] made NodeAddress use ListenIP and ListenPort if not specified

Merge in ZBX/zabbix from feature/ZBX-21510-6.3 to master

* commit '68344a11fbcc9353e102c40f2d6cd3f1189a7f09':
  ........S. [ZBX-21510] changed NodeAddress configuration description to be more descriptive
  ........S. [ZBX-21510] code style fixes
  ........S. [ZBX-21510] additional bit of refactoring to remove static variable
  ........S. [ZBX-21510] refactored HA to remove global variables