Minor data change

Just noticed that the SPC made a very minor edit to their historical data file. As always, this change has been carried over to the Tornado History Project.

The tornado in question is 19681117.28.13, where the lift-off coordinates were changed from 30.8,-88.92 to 31.67,-89.93. While the data has been updated, this had no effect on the map since the approximate path was reproduced with data from the NCDC (see Enhanced Paths Explained), which already had the correct coordinates.