CUPS Web UI: Fix uninitialized variable during driver selection

CUPS Web UI: Fix uninitialized variable during driver selection

If device uri doesn't contain model name, `current_make_and_model` is
uninitialized during driver selection in CUPS Web UI.

The issue manifests itself during choosing IPP Everywhere driver, which
has the variable in its name, so it ends up into
`{current_make_and_model} - IPP Everywhere`.

Since we don't have any info about model at the time, I would propose to
just shorten the driver name for such cases. The PR works that way.