Fix trigger name for upsBasicBatteryStatus monitor.

According to http://support.ipmonitor.com/mibs/POWERNET-MIB/item.aspx?id=upsBasicBatteryStatus

The status of the UPS batteries.  A batteryLow(3) value indicates the UPS will be unable to sustain the current load, and its services will be lost if power is not restored.  The amount of run time in reserve at the time of low battery can be configured by the upsAdvConfigLowBatteryRunTime.

This changes the trigger name to match that of the APC event.