modify competition error message

app/forms/competitions/save_team_form.rb

@@ -16,14 +16,13 @@ class Competitions::SaveTeamForm
   validate :check_teachers_enrollable
   def check_teachers_enrollable
     if competition.teacher_enroll_forbidden? # 禁止老师报名
+      return if creator.is_teacher? # 因为创建者有单独校验，所以这里跳过
       return if teacher_ids.blank?
 
       if teacher_ids.present?
         errors.add(:teacher_ids, :enroll_forbidden)
         return
       end
-
-      return if creator.is_teacher? # 因为创建者有单独校验，所以这里跳过
     end
 
     self.teacher_ids = teacher_ids.map(&:to_i)
@@ -50,14 +49,13 @@ class Competitions::SaveTeamForm
   validate :check_members_enrollable
   def check_members_enrollable
     if competition.member_enroll_forbidden? # 禁止学生报名
+      return unless creator.is_teacher? # 因为创建者有单独校验，所以这里跳过
       return if member_ids.blank?
 
       if member_ids.present?
         errors.add(:member_ids, :enroll_forbidden)
         return
       end
-
-      return unless creator.is_teacher? # 因为创建者有单独校验，所以这里跳过
     end
 
     self.member_ids = member_ids.map(&:to_i)