chore(Scripts/Misc): Cleanup some more JustDied hooks (#9768)

src/server/scripts/Kalimdor/CavernsOfTime/EscapeFromDurnholdeKeep/boss_epoch_hunter.cpp

@@ -75,7 +75,7 @@ public:
 
         void JustDied(Unit* killer) override
         {
-            if (killer == me)
+            if (killer && killer == me)
                 return;
             Talk(SAY_DEATH);
             me->GetInstanceScript()->SetData(DATA_ESCORT_PROGRESS, ENCOUNTER_PROGRESS_EPOCH_KILLED);

src/server/scripts/Kalimdor/CavernsOfTime/EscapeFromDurnholdeKeep/old_hillsbrad.cpp

@@ -494,7 +494,7 @@ public:
 
         void JustDied(Unit* killer) override
         {
-            if (killer == me)
+            if (killer && killer == me)
                 return;
 
             summons.DespawnAll();

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

@@ -194,7 +194,7 @@ public:
             }
         }
 
-        void JustDied(Unit* ) override
+        void JustDied(Unit* /*killer*/) override
         {
             me->SetRespawnTime(DAY);
             events.Reset();