Add "disable pretendo" to unable to update troubleshooting

[stop-posting-not-good-stuff]

Pages with issue(s) Troubleshooting, in the "Unable to update" section

https://3ds.hacks.guide/troubleshooting Description of the issue(s) Disabling Pretendos patches fixed my issue of not being able to update. It seems like turning off third-party servers and switching back to Nintendo's official servers can fix "unable to update". However, it's not listed that turning off services such as Pretendo network can fix this issue. I ended up doing a CTRTransfer for no reason because of this. It wasn't until I talked in the homebrew discord server was I able to find out this was the problem.