fix(Script/Spells): Anti-Magic Zone amount calc (#7438)
fix(Script/Spells): Anti-Magic Zone amount calc (#7438)

* cherry-pick commit (https://github.com/TrinityCore/TrinityCore/commit/bea682f95c374d914f47925448fff6b8c9d3fcb4)

Co-authored-by: Lucas Nascimento <391b1d87f6d81352dcbea95c24babcfbab354936@gmail.com>
Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Helias/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,mygithome002/azerothcore-wotlk,mygithome002/azerothcore-wotlk,azerothcore/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,mygithome002/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Helias/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Helias/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Helias/azerothcore-wotlk,Helias/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,azerothcore/azerothcore-wotlk,azerothcore/azerothcore-wotlk