fix(Core/Spells): Revive Pet cannot be cast if there is not pet to resurrect (#12818)
fix(Core/Spells): Revive Pet cannot be cast if there is not pet to resurrect (#12818)

- Closes #12776
azerothcore/azerothcore-wotlk,mygithome002/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Helias/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Helias/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,azerothcore/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk