BETA: `TriggerSkillByDamage` effect should be disabled if chance or skill level is set to 0.

Reported by: !UnAfraid

git-svn-id: http://svn.l2jdp.com/branches/unstable/L2J_DataPack_BETA@9985 5288da4f-0efc-0310-bd40-8d490a2659fa