fix: battery soc

[bstaeheli]

The tag TAG_EMS_BAT_SOC seems to be the current SOC. The other one is maybe the daily average.

[pvtom]

Hi Boris, thank you.
I think it's correct to use TAG_EMS_BAT_SOC for the current SOC.
I will check what the other value could be. Nothing about it in the documentation. In my opinion the yesterday SOC is the SOC at 23:59 h, but I will check this as well.
BR Thomas