competition: fix

app/forms/competitions/save_team_form.rb

@@ -16,6 +16,8 @@ class Competitions::SaveTeamForm
   validate :check_teachers_enrollable
   def check_teachers_enrollable
     if competition.teacher_enroll_forbidden? # 禁止老师报名
+      return if teacher_ids.blank?
+
       if teacher_ids.present?
         errors.add(:teacher_ids, :enroll_forbidden)
         return
@@ -48,6 +50,8 @@ class Competitions::SaveTeamForm
   validate :check_members_enrollable
   def check_members_enrollable
     if competition.member_enroll_forbidden? # 禁止学生报名
+      return if member_ids.blank?
+
       if member_ids.present?
         errors.add(:member_ids, :enroll_forbidden)
         return