Zabbix

........S. [ZBX-20137] fixed HA node not to become active after restart if there is another node that can take over

Merge in ZBX/zabbix from feature/ZBX-20137-5.5 to master

* commit '9801e3090b9a4a818f750027c25da4bea95c8520':
  ........S. [ZBX-20137] coding style fixes
  ........S. [ZBX-20137] minor refactoring
  .D........ [ZBX-20137] fixed ChangeLog
  .D........ [ZBX-20137] fixed ChangeLog
  ........S. [ZBX-20137] simplified iniital database check delay calculations
  ........S. [ZBX-20137] fixed HA node not become active after restart if there is other node that can take over