Core/BG: Isle of Conquest - fix worldstates

-sometimes not all worldstates were shown correctly
Core/Scripts: Fix possible NULL dereferences

Fix possible NULL dereferences probably caused by a typo.
Merge pull request #11272 from gerripeach/pull_request6

Core/BG: Isle of Conquest - fix worldstates
Core/Transports: Log an error if a Transport has no GameObject template

Log an error if a Transport has no GameObject template from `gameobject_template` table instead of dereferencing NULL .
Merge branch 'master' of github.com:TrinityCore/TrinityCore