Failure during import when processing invalid links

[ldesgrange]

As the comment says:

blogger-importer/blogger-importer.php

Line 655 in 89d7180

@unlink($tmp); // clean up, copied this from other examples but how is this supposed to work if $tmp is an error??

…this line can’t work.

I actually had an error reported here (invalid link), and because of @unlink($tmp);, the import process crashes. I think it will be better to just ignore the link and continue with the next image (replace that line with return $tmp;?).
There are other similar lines in that function, they probably deserve to be fixed the same way as well.