how to change submin server url

[Bingyu1413]

My old reviewboard server ip is "http://192.168.0.140", And my old submin url is:"http://192.168.0.140/submin".
now I changed server ip to 192.168.3.240.
reveiwboard is worked fine.but when I visit "http://192.168.3.240/submin", website changed to "http://192.168.0.140/submin/login/"