Zabbix

...G...... [ZBX-27495] fixed history upload excessive delay for both Zabbix agents

* commit '95da6df02bfd627f121cb2759abf7c54eb797666': (21 commits)
  ...G...... [ZBX-27495] fixed condition for counter restart
  ...G...... [ZBX-27495] updated RefreshActiveChecks logic for agent2
  ...G...... [ZBX-27495] reworked connection checking by rescheduling of refresh_active_checks
  ...G...... [ZBX-27495] reverted Agent connection retry via send_buffer
  ...G...... [ZBX-27495] disabled counter after first failed process_active_checks() call
  ...G...... [ZBX-27495] fixed work with static vaiable
  ...G...... [ZBX-27495] improved detection of communication problems related only to network errors
  ...G...... [ZBX-27495] fixed uploadRetryAfter for configuration updating
  ...G...... [ZBX-27495] fixed uploadRetryAfter variable
  ...G...... [ZBX-27495] refactored code for jenkins agent2 build test
  ...G...... [ZBX-27495] updated mockWriter signature
  ...G...... [ZBX-27495] restored serverconnector.go
  ...G...... [ZBX-27495] refactored retry connection logic for agent2
  ...G...... [ZBX-27495] reworked solution for A1
  ...G...... [ZBX-27495] added Changelog file
  ...G...... [ZBX-27495] replaced pullForwardActiveChecksRefresh()
  ...G...... [ZBX-27495] restored debug level for agent2
  ...G...... [ZBX-27495] restored debug level for agent
  ...G...... [ZBX-27495] added retry connection logic for agent2
  ...G...... [ZBX-27495] removed redundant comment
  ...