修改bug，课程动态报错

lib/plugins/acts_as_activity_provider/lib/acts_as_activity_provider.rb

@@ -98,20 +98,13 @@ module Redmine
             # Author lizanle
             # Description 删除 unless scope.all，因为这个执行查询，并且没有加入时间限制，与下边 scope.all(provider_options[:find_options].dup)重复
             if options[:course]
-              if provider_options[:timestamp].include? "updated_on"
-                to = scope.scoped(:order => "#{provider_options[:timestamp]} desc").all(provider_options[:find_options].dup).first.updated_on
-              else
-                to = scope.scoped(:order => "#{provider_options[:timestamp]} desc").all(provider_options[:find_options].dup).first.created_on
-              end
-                from = (to - days.days) > created_time ? (to - days.days) : created_time.to_date
+              scope.all(provider_options[:find_options].dup)
             else
-                #from =  to - Setting.activity_days_default.to_i
-            end
-
-            if from && to
-              scope = scope.scoped(:conditions => ["#{provider_options[:timestamp]} BETWEEN ? AND ?", from, to])
+              if from && to
+                scope = scope.scoped(:conditions => ["#{provider_options[:timestamp]} BETWEEN ? AND ?", from, to])
+                scope.all(provider_options[:find_options].dup)
+              end
             end
-            scope.all(provider_options[:find_options].dup)
           end
 
           # 为了首页获取数据基本复制了上面的方法，改变了用户查看权限，增加了对讨论区的识别。