v1.2.1 - Live NPC HP Fixes

• This fixes an error that would come up when visiting an NPC sheet that wasn't in the combat tracker yet.
• It also contains a rule clarification for 3.5E which doesn't use CHA for undead.

See previous release:
https://github.com/bmos/FG-PFRPG-Live-Hitpoints-from-Constitution/releases/tag/v1.2.0