man-db: upgrade 2.11.1 -> 2.11.2

man-db: upgrade 2.11.1 -> 2.11.2

Changelog:
=========
Fixes:
------
 * Fix compile and test failures when 'troff' is not 'groff'.
 * Fix segfault in typical uses of 'man' when 'nroff' is not installed.
 * Fix crash in 'mandb' when processing stray cats.

Improvements:
-------------
 * Check for stray cats even if no manual pages in a given manpath were
   changed.

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>