Core/AI: silence a freaking annoying VS IntelliSense warning

(cherry picked from commit 0eb5d240fa)

src/server/game/Scripting/ScriptMgr.cpp

@@ -1166,12 +1166,6 @@ private:
     if (!V) \
         return R;
 
-struct TSpellSummary
-{
-    uint8 Targets;                                          // set of enum SelectTarget
-    uint8 Effects;                                          // set of enum SelectEffect
-} *SpellSummary;
-
 ScriptObject::ScriptObject(char const* name) : _name(name)
 {
     sScriptMgr->IncreaseScriptCount();