Scripts/Misc: added a few pointer checks in JustDied hook overrides

src/server/scripts/EasternKingdoms/zone_westfall.cpp

@@ -362,7 +362,7 @@ struct npc_westfall_hobo_witness : public ScriptedAI
 
     void JustDied(Unit* who) override
     {
-        if (who->IsCreature() && who->ToCreature()->IsAIEnabled())
+        if (who && who->IsCreature() && who->ToCreature()->IsAIEnabled())
             who->ToCreature()->AI()->DoAction(ACTION_AGGRO_HOBO_DONE);
         me->CastSpell(me, SPELL_SUMMON_RAGAMUFFIN_LOOTER);
     }

src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp

@@ -151,7 +151,7 @@ public:
 
         void JustDied(Unit* killer) override
         {
-            if (killer->GetEntry() == me->GetEntry())
+            if (killer && killer->GetEntry() == me->GetEntry())
                 return;
 
             Talk(SAY_DEATH);