On attempt to send signal to Zabbix during startup log message says: "cannot redirect signal: shutdown in progress"

$ zabbix_server -c /path/to/config && zabbix_server -c /path/to/config -R log_level_increase

 12252:20170127:161843.849 Starting Zabbix Server. Zabbix 3.3.0 (revision {ZABBIX_REVISION}).
 12252:20170127:161843.849 ****** Enabled features ******
 12252:20170127:161843.850 SNMP monitoring:            NO
 12252:20170127:161843.850 IPMI monitoring:            NO
 12252:20170127:161843.850 Web monitoring:             NO
 12252:20170127:161843.850 VMware monitoring:          NO
 12252:20170127:161843.850 SMTP authentication:        NO
 12252:20170127:161843.850 Jabber notifications:       NO
 12252:20170127:161843.850 Ez Texting notifications:   NO
 12252:20170127:161843.850 ODBC:                       NO
 12252:20170127:161843.850 SSH2 support:               NO
 12252:20170127:161843.850 IPv6 support:               NO
 12252:20170127:161843.850 TLS support:                NO
 12252:20170127:161843.850 ******************************
 12252:20170127:161843.850 using configuration file: /home/gleb/zabbix-config/server/trunk_postgresql.conf
 12252:20170127:161843.850 loaded modules: dummy.so
 12252:20170127:161843.865 cannot redirect signal: shutdown in progress
 12252:20170127:161843.865 current database version (mandatory/optional): 03030022/03030022
 12252:20170127:161843.865 required mandatory version: 03030022
 12252:20170127:161843.886 server #0 started [main process]
...