message: build: remove workaround for Boost and std::atomic
diff: @@ -1448,11 +1448,6 @@ if test x$use_boost = xyes; then
  BOOST_CPPFLAGS=SUPPRESS_WARNINGS($BOOST_CPPFLAGS)
  fi
  - dnl Boost 1.56 through 1.62 allow using std::atomic instead of its own atomic
  - dnl counter implementations. In 1.63 and later the std::atomic approach is default.
  - m4_pattern_allow(DBOOST_AC_USE_STD_ATOMIC) dnl otherwise it's treated like a macro
  - BOOST_CPPFLAGS="-DBOOST_SP_USE_STD_ATOMIC -DBOOST_AC_USE_STD_ATOMIC $BOOST_CPPFLAGS"
  -
  BOOST_LIBS="$BOOST_LDFLAGS $BOOST_SYSTEM_LIB $BOOST_FILESYSTEM_LIB"
  fi
  