Update plugin release to 2.5.4
Update plugin release to 2.5.4

Change-Id: I1aef9c4abcc4f11cec03db8b2db34b3021467996

stackforge/fuel-plugin-external-zabbix,stackforge/fuel-plugin-external-zabbix,stackforge/fuel-plugin-external-zabbix,stackforge/fuel-plugin-external-zabbix