Core/Misc: Fix issues reported by static analysis

(cherry picked from commit 33dace231c5a169375523ffa89a2cc3fa48737bd)

src/server/game/Spells/SpellEffects.cpp

@@ -802,6 +802,7 @@ void Spell::EffectTriggerRitualOfSummoning()
 void Spell::CalculateJumpSpeeds(SpellEffectInfo const* effInfo, float dist, float& speedXY, float& speedZ)
 {
     Unit* unitCaster = GetUnitCasterForEffectHandlers();
+    ASSERT(unitCaster);
     float runSpeed = unitCaster->IsControlledByPlayer() ? playerBaseMoveSpeed[MOVE_RUN] : baseMoveSpeed[MOVE_RUN];
     if (Creature* creature = unitCaster->ToCreature())
         runSpeed *= creature->GetCreatureTemplate()->speed_run;