Fix SpellAurasEffects build on GCC 5.1

Closes #14655

(cherry picked from commit 57ced3ccbd44c8d4955da645522c6cd85c001c6c)

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -33,6 +33,7 @@
 #include "Battleground.h"
 #include "OutdoorPvPMgr.h"
 #include "GridNotifiers.h"
+#include "GridNotifiersImpl.h"
 #include "ScriptMgr.h"
 #include "Vehicle.h"
 #include "Battlefield.h"