Zabbix

.......PS. [ZBXNEXT-10224] moved zbx_vault_renew_token() calls to main processes, simplified zbx_vault_init()

This commit separates zbx_vault_init() from zbx_vault_renew_token() by moving zbx_vault_renew_token()
call a level up, into main process where other calls to zbx_vault_renew_token() are made.
The new design is simpler, easier to understand.