When inventory is not found, a link is rendered

[brotkrueml]

I defined a reference in the guides.xml and used it on a page:

:ref:`My link text <remote_inv:introduction>`

But the "remote_inv" is not found:

app.WARNING: Interlink inventory not found: HTTP/2 404

Then the following link is rendered:

<a href="#introduction">My link text</a>

This is obviously wrong. Instead, no link should be generated, but just the text:

My link text