fix fPBr() regex

[mkdgs]

a very big text on one line (~10 000 chars) causes internal server error. It will be significantly faster

[netcarver]

Thanks Mickael. This is in the new dev branch and will be part of the next release.

[netcarver]

Hello Mickael. Although this issue is now closed, I wonder if you might be able to supply me with a file of the text that was causing your original parse failure? The reason I'm asking is because I have another change to make to the fPBr() regex and I want to make sure it doesn't re-introduce the problem.

[netcarver]

Hang on, missed the "on one line" part -- I can generate that myself, sorry to have bothered you.

[netcarver]

I can't reproduce this even with ~50 000 characters on a line.