spr fails after githubHost changed

[jonathanloske]

We just moved our repository from one host to another. Subsequently, I updated .spr.yml to point to the new repo. Unfortunately, spr is very unhappy with this:

❯ git spr status           
> git rev-parse --show-toplevel
> github fetch pull requests
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x0 pc=0x101059478]

goroutine 1 [running]:
github.com/ejoffe/spr/github/githubclient.(*client).GetInfo(0x140000a2a38, {0x1012444f0?, 0x101561500?}, {0x101244410, 0x140000a2a20})
        /Users/runner/work/spr/spr/github/githubclient/client.go:200 +0x138
github.com/ejoffe/spr/spr.(*stackediff).StatusPullRequests(0x140000acfc0, {0x1012444f0, 0x101561500})
        /Users/runner/work/spr/spr/spr/spr.go:349 +0x74
main.main.func2(0x14000218d80?)
        /Users/runner/work/spr/spr/cmd/spr/main.go:134 +0x28
github.com/urfave/cli/v2.(*Command).Run(0x14000218d80, 0x140000af440)
        /Users/runner/go/pkg/mod/github.com/urfave/cli/v2@v2.8.1/command.go:169 +0x4f8
github.com/urfave/cli/v2.(*App).RunContext(0x14000083860, {0x1012444f0?, 0x101561500}, {0x140000ba000, 0x2, 0x2})
        /Users/runner/go/pkg/mod/github.com/urfave/cli/v2@v2.8.1/app.go:341 +0x85c
github.com/urfave/cli/v2.(*App).Run(...)
        /Users/runner/go/pkg/mod/github.com/urfave/cli/v2@v2.8.1/app.go:247
main.main()
        /Users/runner/work/spr/spr/cmd/spr/main.go:230 +0x1208

This can be reproduced by having set a custom githubHost and then updating it to github.com.