[1.11.x] Fixed #29094 -- Fixed crash when entering an invalid uuid in ModelAdmin.raw_id_fields.

      Regression in 2f9861d823620da7ecb291a8f005f53da12b1e89.

Thanks Carel Burger for the report and fix.

Backport of docs552abffab16cbdff571486b683e7e7ef12e46066 from master