Question.update_last_target does not always set a value for last_target_date so use updated_at when last_target_date nil
Question.update_last_target does not always set a value for last_target_date
so use updated_at when last_target_date nil

ricodigo/shapado,gravityrail/shapado,ooohiroyukiooo/shapado,10xEngineer/shapado,cctuan/shapado_g,gravityrail/shapado,NazarK/shapado,cctuan/shapado_g,amyhua/QnA,stan/shapado,cctuan/shapado_g,ooohiroyukiooo/shapado,ricodigo/shapado,sinnerex/zoorab,stan/shapado,amyhua/QnA,stan/shapado,sinnerex/zoorab,ricodigo/shapado,sinnerex/zoorab,10xEngineer/shapado,NazarK/shapado,ooohiroyukiooo/shapado,NazarK/shapado,ooohiroyukiooo/shapado,10xEngineer/shapado,stan/shapado,amyhua/QnA,gravityrail/shapado