Random crash during usage

This came up while I was working. I can pull out more from screen recordings if the call stack alone doesn't give enough context.

```csharp
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x106d1be]

goroutine 1 [running]:
github.com/jesseduffield/gocui.(*View).draw(0xc000148b40, 0x1781184, 0xe)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:796 +0x4d2
github.com/jesseduffield/gocui.(*Gui).draw(0xc0000c56c0, 0xc000148b40, 0x100000007, 0x0)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:1047 +0x105
github.com/jesseduffield/gocui.(*Gui).flush(0xc0000c56c0, 0x0, 0x0)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:732 +0x278
github.com/jesseduffield/gocui.(*Gui).MainLoop(0xc0000c56c0, 0xc000000004, 0xc00031fa08)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:622 +0x20f
github.com/jesseduffield/lazygit/pkg/gui.(*Gui).Run(0xc0000e0380, 0x0, 0x0)
/home/runner/work/lazygit/lazygit/pkg/gui/gui.go:540 +0x51b
github.com/jesseduffield/lazygit/pkg/gui.(*Gui).RunAndHandleError.func1(0xc000280001, 0xc000262540)
/home/runner/work/lazygit/lazygit/pkg/gui/gui.go:548 +0x45
github.com/jesseduffield/lazygit/pkg/utils.SafeWithError(0xc00031fb40, 0x0, 0x0)
/home/runner/work/lazygit/lazygit/pkg/utils/utils.go:380 +0x62
github.com/jesseduffield/lazygit/pkg/gui.(*Gui).RunAndHandleError(0xc0000e0380, 0x0, 0x10000000177ea17)
/home/runner/work/lazygit/lazygit/pkg/gui/gui.go:547 +0x7d
github.com/jesseduffield/lazygit/pkg/app.(*App).Run(0xc0002bc150, 0xc00024a5a0, 0x0)
/home/runner/work/lazygit/lazygit/pkg/app/app.go:242 +0x6b
main.main()
/home/runner/work/lazygit/lazygit/main.go:127 +0xb7b
```

Reproduced on 0.28.1.