Fixed a bug with adding a Segment
Fixed a bug with adding a Segment

If you didn't specify a Segment History yourself, the segment had
a null Segment History which caused a lot of issues with a lot of
simpler Run Factories.

Jiiks/LiveSplit,Jiiks/LiveSplit,LiveSplit/LiveSplit,zoton2/LiveSplit,chloe747/LiveSplit,zoton2/LiveSplit,Dalet/LiveSplit,Dalet/LiveSplit,ROMaster2/LiveSplit,kugelrund/LiveSplit,Dalet/LiveSplit,chloe747/LiveSplit,kugelrund/LiveSplit,stoye/LiveSplit,kugelrund/LiveSplit,stoye/LiveSplit,zoton2/LiveSplit,ROMaster2/LiveSplit,Glurmo/LiveSplit,PackSciences/LiveSplit,Glurmo/LiveSplit,Fluzzarn/LiveSplit,PackSciences/LiveSplit,PackSciences/LiveSplit,Jiiks/LiveSplit,Fluzzarn/LiveSplit,Fluzzarn/LiveSplit,stoye/LiveSplit,Glurmo/LiveSplit,ROMaster2/LiveSplit,chloe747/LiveSplit