Why is there a space in the bowdlerised "L– ." in Jane Eyre?

I have been reading Jane Eyre recently and came across a sentence the other day:

...and away we rattled over the “stony street” of L— .

There is a blank between "–" and the full stop, which made me quite confused. I know that the reason why the author used "L" instead of a concrete name is avoid to reveal someone's private information or be sued for libel, but this blank still perplexes me.

Why is there a space before the full stop? Is it a typo? If not, what does it mean?

In wikisource.org I found a page of what purports to be the first edition, which shows

There's no reason to include a space before the full stop, and it's a misprint.

In passing, it's interesting to note the uneven spacing of words in the top line of that image. Hot metal letterpress wasn't an exact science, at least until Linotype, but there's generally no space before a full stop and here is no exception.