Core/Misc: Fix static analysis issues

src/server/game/Battlegrounds/BattlegroundMgr.cpp

@@ -1217,7 +1217,6 @@ BattlegroundTypeId BattlegroundMgr::GetRandomBG(BattlegroundTypeId bgTypeId)
 {
     if (BattlegroundTemplate const* bgTemplate = GetBattlegroundTemplateByTypeId(bgTypeId))
     {
-        BattlegroundSelectionWeightMap selectionWeights;
         std::vector<BattlegroundTypeId> ids;
         ids.reserve(16);
         std::vector<double> weights;