bugfix: fix nil target

src/models/user.go

@@ -462,6 +462,10 @@ func (u *User) BusiGroups(limit int, query string, all ...bool) ([]BusiGroup, er
 				return lst, err
 			}
 
+			if t == nil {
+				return lst, nil
+			}
+
 			err = DB().Order("name").Limit(limit).Where("id=?", t.GroupId).Find(&lst).Error
 		}