fix accidental override of completed description when constructing quest pointer for player

EQ2/source/WorldServer/Quests.cpp

@@ -388,7 +388,6 @@ Quest::Quest(Quest* old_quest){
 	quest_state_temporary = false;
 	tmp_reward_status = 0;
 	tmp_reward_coins = 0;
-	completed_description = string("");
 	quest_temporary_description = string("");
 }