
libtidy was needed "for python-tidy, used by sphinxcontrib-docbookrestapi". sphinxcontrib-docbookrestapi is retired as stackforge project. There are three repositories using it in test-requirements but those do not build any documents - and installing sphinxcontrib-docbookrestapi works even without libtidy installed. libtidy is in bindep-fallback, so can get removed here. Change-Id: I2140917471b09e4d4d53652f4d608ea4c7df65db