Handle faction save/load properly when player has faction reputation in a faction he is not a member of (Fixes #1573)

components/esm/npcstats.cpp

@@ -4,7 +4,7 @@
 #include "esmreader.hpp"
 #include "esmwriter.hpp"
 
-ESM::NpcStats::Faction::Faction() : mExpelled (false), mRank (0), mReputation (0) {}
+ESM::NpcStats::Faction::Faction() : mExpelled (false), mRank (-1), mReputation (0) {}
 
 void ESM::NpcStats::load (ESMReader &esm)
 {
@@ -98,7 +98,7 @@ void ESM::NpcStats::save (ESMWriter &esm) const
             esm.writeHNT ("FAEX", expelled);
         }
 
-        if (iter->second.mRank)
+        if (iter->second.mRank >= 0)
             esm.writeHNT ("FARA", iter->second.mRank);
 
         if (iter->second.mReputation)