Fix broken version compare in jquery-migrate

[Krinkle]

No description provided.

[Krinkle]

This change fixes the broken build that we've had for a few months now.

I wonder why that version compare is there in the first place. How about we fix it in src/? so that it consistently returns a string instead of undefined (e.g. the old behaviour that one would expect the migrate plugin restores).

Although I suppose that would break it for code that has already updated and now relies on it returning undefined (the new behaviour). Is migrate only supposed to cover API changes when they're non-breaking for code that has already migrated to work with the latest version? I guess so. So we'll keep this version compare then.

[dmethvin]

Oh that's some bad code right there. I think it's mine. The problem was figuring out how to "feature test" the changed behavior, given that Migrate needs to work with 1.6.4 or later (including 1.10.2 for example). I can't recall the details of it right now though. The patch here will fix it so we can land it if there aren't any better ideas.

[gibson042]

👍