message: das.named: Fix `map` test.
diff: @@ -345,8 +345,8 @@ void
  map()
  {
  auto p = elle::das::named::prototype(foo = boost::none);
  - BOOST_CHECK(!boost::optional<int>(p.map().foo));
  - BOOST_CHECK_EQUAL(p.map(42).foo, 42);
  + BOOST_CHECK(!p.map<boost::optional<int>>().foo);
  + BOOST_CHECK_EQUAL(p.map<boost::optional<int>>(42).foo, 42);
  }
  /*-------.
  