Some system update buggered HAL again, no two batteries show up in my lshal output, and hence in Solid, and hence in the Battery applet.

So quickly fix the battery applet to work with more than one battery (I don't have a physical second battery, so it's a great opportunity I get now).

Thanks to the HAL people and my OSV's QA department forletting this slip through -- it'll improve the battery applet in 4.2.