boost: fix build error with recent versions of glibc

Original patch is at https://svn.boost.org/trac/boost/changeset/84950

Signed-off-by: Yvan Volochine <yvan.volochine@gmail.com>
Merge pull request #988 from gusano/topic/boost_fix_for_recent_glibc

boost: fix build error with recent versions of glibc