Core/Scripts: Added a missing break in Illidan Stormrage script

Thanks Jackpoz

src/server/scripts/Outland/BlackTemple/boss_illidan.cpp

@@ -519,6 +519,7 @@ public:
                     events.ScheduleEvent(EVENT_SHADOW_BLAST, Seconds(1), group);
                     events.ScheduleEvent(EVENT_FLAME_BURST, Seconds(6), group);
                     events.ScheduleEvent(EVENT_SHADOW_DEMON, Seconds(18), Seconds(30), group);
+                    break;
                 case GROUP_PHASE_4:
                     ScheduleEvents(GROUP_PHASE_3, group);
                     events.ScheduleEvent(EVENT_FRENZY, Seconds(40), group);