fixed 删除用户时保留项目动态数据

app/views/project_trends/_detail.json.jbuilder

@@ -4,7 +4,7 @@ json.action_type l("trend.#{trend.action_type}") + l("trend.#{trend.trend_type}"
 json.trend_id trend.trend_id
 json.user_name trend.user.try(:show_real_name)
 json.user_login trend.user&.login
-json.user_avatar url_to_avatar(trend.user)
+json.user_avatar trend.user.blank?? User::Avatar.get_letter_avatar_url("D") : url_to_avatar(trend.user)
 json.action_time time_from_now(trend.created_at)
 json.project do 
   json.owner do