Core/Spells: always initialize hitinfo aura

Ref 437c5c7b9d2122f7b1f46fd4e0f502c8be1e3091

(cherry picked from commit 07e42f7d4121e18f6f61cafe8e6fe389ff8b1beb)

src/server/game/Spells/Spell.cpp

@@ -2907,10 +2907,9 @@ void Spell::DoSpellEffectHit(Unit* unit, SpellEffectInfo const& spellEffectInfo,
                 }
             }
             else
-            {
-                hitInfo.HitAura = _spellAura;
                 _spellAura->AddStaticApplication(unit, aura_effmask);
-            }
+
+            hitInfo.HitAura = _spellAura;
         }
     }