Remove serializer::chunked (API Change):

* The function serializer::chunked is removed,
  since it is redundant.

Actions Required:

* Call serializer::get::chunked instead of serializer::chunked

include/boost/beast/http/impl/file_body_win32.ipp

@@ -410,7 +410,7 @@ operator()()
         return detail::async_write_some(
             sock_, sr_, std::move(*this));
     }
-    if(sr_.chunked())
+    if(sr_.get().chunked())
     {
         return detail::async_write_some(
             sock_, sr_, std::move(*this));
@@ -501,7 +501,7 @@ write_some(
             return bytes_transferred;
         return bytes_transferred;
     }
-    if(sr.chunked())
+    if(sr.get().chunked())
     {
         auto const bytes_transferred =
             detail::write_some(sock, sr, ec);

include/boost/beast/http/impl/serializer.ipp

@@ -77,8 +77,7 @@ next(error_code& ec, Visit&& visit)
     {
         frdinit(std::integral_constant<bool,
             isRequest>{});
-        chunked_ = m_.chunked();
-        if(chunked_)
+        if(m_.chunked())
             goto go_init_c;
         s_ = do_init;
         BOOST_BEAST_FALLTHROUGH;