Add support to patch nim to use an other Update server

[Hartie95]

Like @Syphurith suggested here: cdffb5e
I will add a menu Entry to read a server URL from an txt file, patch the nim urls and start the sytemsettings. This will allow users to easy update to a spezific firmware.
I found the following urls inside of nim(9.0):
https://ecs.c.shop.nintendowifi.net/ecs/services/ECommerceSOAP
2x https://nus.c.shop.nintendowifi.net/nus/services/NetUpdateSOAP
2x https://ecs.c.shop.nintendowifi.net/ecs/services/ECommerceSOAP
https://ias.c.shop.nintendowifi.net/ias/services/IdentityAuthenticationSOAP

[Syphurith]

Also to note, since it would actually try to connect conntest.nintendowifi.net you can also search for this in ac module and replace to a static page link that is shorter than the original length. This works for me and make 3ds thinks it is alway online, thus get rid of occasionally streetpass test.