fix(Core/Misc): all GCC warnings (#3457)

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

@@ -238,7 +238,10 @@ public:
                 {
                     instance->LoadGrid(instancePositions[2].GetPositionX(), instancePositions[2].GetPositionY());
                     if (Creature* drake = instance->SummonCreature(NPC_LIEUTENANT_DRAKE, instancePositions[2]))
+                    {
                         drake->AI()->Talk(0);
+                    }
+                    [[fallthrough]]; // TODO: Not sure whether the fallthrough was a mistake (forgetting a break) or intended. This should be double-checked.
                 }
                 case EVENT_THRALL_REPOSITION:
                 {