[spaetz]

Thanks for improving the pdf output, but it seems like the pdf download for the paid Economist feed is now broken in 0.6.54, I get that crash:

creating PDF Output...
Converting input as a text based book...
Serializing oeb input to disk for processing...
Traceback (most recent call last):
File "/tmp/init.py", line 48, in <module>
File "/home/kovid/build/calibre/src/calibre/utils/ipc/worker.py", line 99, in main
File "/home/kovid/build/calibre/src/calibre/gui2/convert/gui_conversion.py", line 24, in gui_convert
File "/home/kovid/build/calibre/src/calibre/ebooks/conversion/plumber.py", line 919, in run
File "/home/kovid/build/calibre/src/calibre/ebooks/pdf/output.py", line 88, in convert
File "/home/kovid/build/calibre/src/calibre/ebooks/pdf/output.py", line 98, in convert_text
File "/home/kovid/build/calibre/src/calibre/ebooks/epub/output.py", line 170, in insert_cover
AttributeError: 'OptionValues' object has no attribute 'preserve_cover_aspect_ratio'