Opera Addons rejects Adblock Plus because of ML model format

Submitting Adblock Plus 3.8 to Opera Addons fails with following error:

Invalid type on file: data/mlHideIfGraphMatches/group1-shard1of1.bin

Sorry for the brief issue description, but I'm in the middle of a release right now. But also I don't have any more information.

But FWIW file (libmagic) recognizes the file as DOS executable, and I have a hunch that Opera Addons detects the mimetype and rejects any extension package that includes any files that appear suspicious based on the detected mimetype.

Hints for testers

The model name has changed, we need to make sure the snippet still works, when ML snippet is enabled.

/cc @shoniko @skipintro @kzar