libcupsfilters: Make pdftopdf() also work correctly with auro-rotating off

libcupsfilters: Make pdftopdf() also work correctly with auro-rotating off

If one turns off auto-rotating in the pdftopdf() filter function
(option "nopdfAutoRotate") the orientation of the input page on the
output sheet is manually controlled by the options
"orientation-requested" and "landscape".

The cropping of the pages (with "print-scaling=none") did not work
correctly with auto-rotating turned off. This commit fixes this.

Now all should work correctly as described here:

https://openprinting.github.io/cups/doc/options.html
https://wiki.debian.org/CUPSPdfToPdf