Fixes some roundstart runtimes relating to set_species().

Corpses on away missions and such were calling set_species() since that is called in human New(), but the hair/underwear lists weren't initialized at that time, so their len was null, so zero division happened.

Big thanks to @wild-billy for telling me about these runtimes and pointing me to his PR that fixes them for vg. (d3athrow/vgstation13#1487)