Log Message:
print/ruby-pdf-reader: update to 2.4.0

Update ruby-pdf-reader to 2.4.0.

2.4.0 (21st November 2019)

- Optimise overlapping characters code introduced in 2.3.0. Text extraction
  of pages with thousands of characters is still slower than it was in
  2.2.1, but it might tolerable for now.
  See https://github.com/yob/pdf-reader/pull/308 for details.

- Implement very basic font substitution for Type1 and TrueType fonts that
  aren't embedded

- Remove PDF::Hash class. It's been deprecated since 2010, and it's hard to
  believe anyone is still using it.

- Several small bug fixes

2.3.0 (7th November 2019)

- Text extraction now makes an effort to skip duplicate characters that
  overlap, a common approach used for a fake "bold" effect, This will make
  text extraction a bit slower - if that turns out to be an issue I'll look
  into further optimisations or provide a toggle to turn it off

- Several small bug fixes