Update line and loads source data

[FredericSabot]

Hello,

In https://github.com/GridMod/RTS-GMLC/tree/master/RTS_Data/SourceData, the branch.csv and bus.csv are inconsistent with the RTS-GMLC_updates.md: lines 11-13 are still present in branch.csv, and the loads have their old values in bus.csv.

The generators are correctly updated in the gen.csv file however.