Core/Gossip: Add missing check for only class trainers in 46374bf533987b492abd590d7cd2ae182b35bd39
DB/Quests: Fix Adding Injury to Insult, closes #3848

Improves b85e4eb72437fa3ecfa5be6f84dedbbd683a9db3
DB/Quests: Fix Badlands Reagent Run II, closes #9880

Thanks @joschiwald and @Kirkhammett
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore