message: reduce Boost requirement to 1.58
diff: @@ -27,8 +27,8 @@ PKG_CHECK_MODULES(LIBEVENT, [libevent], [], [AC_MSG_ERROR([libevent not found])]
  PKG_CHECK_MODULES(ZLIB, [zlib], [], [AC_MSG_ERROR([zlib not found])])
  AC_CHECK_LIB([pthread], [pthread_self], , [AC_MSG_ERROR([libpthread not found.])])
  AC_LANG_CPLUSPLUS
  -AC_CHECK_LIB([snappy], [main])
  -BOOST_REQUIRE([1.62])
  +#AC_CHECK_LIB([snappy], [main])
  +BOOST_REQUIRE([1.58])
  BOOST_SYSTEM([mt])
  BOOST_CHRONO([mt])
  BOOST_FILESYSTEM([mt])
  