System python sets "python" to python2 when /usr/bin/python is python3

OS: Void Linux

Without asdf-python installed: The system handles invocation of python commands. I can type `python2` or `python3` to invoke the specified version. I can also type `python` (which I am used to doing) and in this system, that is symlinked to `python3`.

With asdf-python installed: I still would like to use the system python when I haven't manually selected a different version.
I configured it with the command: `asdf global python system`
However, now the `python` command (`$HOME/.asdf/shims/python`) executes `python2` instead.

This may also be an issue in Ubuntu or Debian when the `python-is-python3` package is installed, but I haven't tested that yet.

Beginne damit, das Verhalten über $HOME/.asdf/shims/python nach dem Ausführen von `asdf global python system` zu reproduzieren, und vergleiche es mit den Systembefehlen `python`, `python2` und `python3`. Untersuche den asdf-python-Shim und das Verhalten bei der Versionsauswahl; abgeschlossen ist dies, wenn die Systemauswahl bewirkt, dass `python` das System-Python 3 statt Python 2 aufruft.

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