Use zabbix_agentd rather than zabbix_agent for erp5 instanciation.

zabbix_agentd is  a standalone  daemon which can  be ran  through supervisord,
whereas zabbix_agent is  supposed to be used with inetd,  thus use the former,
likewise zabbix-agent software instanciation profile.

software/erp5/instance.cfg

@@ -32,7 +32,7 @@ runzope_binary = ${buildout:bin-directory}/runzope
 tidstorage_repozo_binary = ${buildout:bin-directory}/tidstorage_repozo
 tidstoraged_binary = ${buildout:bin-directory}/tidstoraged
 xtrabackup_binary = ${xtrabackup:location}/bin/xtrabackup_51
-zabbix_agent_binary = ${zabbix-agent:location}/sbin/zabbix_agent
+zabbix_agentd_binary = ${zabbix-agent:location}/sbin/zabbix_agentd
 mk-variable-advisor_binary = ${perl:siteprefix}/bin/mk-variable-advisor
 mk-table-usage_binary = ${perl:siteprefix}/bin/mk-table-usage
 mk-visual-explain_binary = ${perl:siteprefix}/bin/mk-visual-explain