Only apply edit policy setting if message changed (#6930)

app/post.go

@@ -256,7 +256,7 @@ func UpdatePost(post *model.Post, safeUpdate bool) (*model.Post, *model.AppError
 		}
 
 		if utils.IsLicensed {
-			if *utils.Cfg.ServiceSettings.AllowEditPost == model.ALLOW_EDIT_POST_TIME_LIMIT && model.GetMillis() > oldPost.CreateAt+int64(*utils.Cfg.ServiceSettings.PostEditTimeLimit*1000) {
+			if *utils.Cfg.ServiceSettings.AllowEditPost == model.ALLOW_EDIT_POST_TIME_LIMIT && model.GetMillis() > oldPost.CreateAt+int64(*utils.Cfg.ServiceSettings.PostEditTimeLimit*1000) && post.Message != oldPost.Message {
 				err := model.NewAppError("UpdatePost", "api.post.update_post.permissions_time_limit.app_error", map[string]interface{}{"timeLimit": *utils.Cfg.ServiceSettings.PostEditTimeLimit}, "", http.StatusBadRequest)
 				return nil, err
 			}