Cannot set any config to empty string

[oae]

Describe the bug

When I try to update the config to an empty string, mangal panics with the following error.

➜  mangal config set --key "gen.author" --value ""
panic: runtime error: index out of range [0] with length 0

goroutine 1 [running]:
github.com/metafates/mangal/cmd.glob..func3(0x1d1c8e0?, {0x10183f8?, 0x4?, 0x4?})
    github.com/metafates/mangal/cmd/config.go:133 +0x829
github.com/spf13/cobra.(*Command).execute(0x1d1c8e0, {0xc000432c40, 0x4, 0x4})
    github.com/spf13/cobra@v1.6.1/command.go:920 +0x847
github.com/spf13/cobra.(*Command).ExecuteC(0x1d1c040)
    github.com/spf13/cobra@v1.6.1/command.go:1044 +0x3bd
github.com/spf13/cobra.(*Command).Execute(...)
    github.com/spf13/cobra@v1.6.1/command.go:968
github.com/metafates/mangal/cmd.Execute()
    github.com/metafates/mangal/cmd/root.go:112 +0x7a
main.main()

Reproduction steps

1. Execute mangal config set --key "gen.author" --value ""

Expected behavior

The command should set the value to an empty string

Additional context

This happened after version 4.0.5

Operating System

Linux

[metafates]

Oh, that's weird, I'll take a look