Update kezan.cpp

[x] Trolls can work now on Kaja Deposit after tased by players.
[x] The aura added by the spell 45870 is no longer displayed on players after killingCredit a troll.
[x] Now the players can't spamming the same troll for completed the quest objectives.
[  ] Troll despawn tased by a player after two minutes (not work correctly)
[  ] Trolls are not sleeping only they can dance, sit or stand too (I need to fix that)