Install bug for neovim with custom $XDG_CONFIG_HOME
## Expected behavior, english is required
when XDG_CONFIG_HOME is set i expect the install script to install into $XDG_CONFIG_HOME/nvim
instead it tried to install $XDG_CONFIG_HOME/**config**/nvim
## The reproduce ways from Vim starting (Required!)
This is an install error not a startup error
## Output of the `:SPDebugInfo!`

## Screenshots

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