fix for error caused by factionless nymphs

Source/ThinkTreeNodes/ThinkNode_ConditionalNympho.cs

@@ -11,7 +11,7 @@ namespace rjw
 		protected override bool Satisfied(Pawn p)
 		{
 			if (xxx.is_nympho(p))
-				if (!p.Faction.IsPlayer)
+				if (p.Faction == null || !p.Faction.IsPlayer)
 					return false;
 				else
 					return true;