Match coefficient C2 for vs150 to Table F1

[jaltekruse-usgs]

C2 coefficient in Wong21-150.csv does not match Table F1 for 0.5 >= T >= 0.03 s, which are positive in the Appendix.

C2 is negative in this period range in the other Vs tables, so it seems possible that the error is in table F1 and not in Wong21-150.csv.

[jaltekruse-usgs]

Bob Darragh confirmed C2 coefficient in Table F1 (for the periods in question) are supposed to be negative (typos in the Appendix tables), so our coefficient file is correct as is. Closing this merge request