fixed issue关闭时，到期结束时间更新

app/services/api/v1/issues/update_service.rb

@@ -88,6 +88,7 @@ class Api::V1::Issues::UpdateService < ApplicationService
       @updated_issue.project_id = @project_id unless @project_id.nil?
       @updated_issue.updated_on = Time.now
       @updated_issue.changer_id = @current_user.id
+      @updated_issue.due_date = Time.now if @due_date.blank?
       @updated_issue.save!
 
       build_after_issue_journal_details if @updated_issue.previous_changes.present? # 操作记录