Merge branch 'dev/roschuma/host_based_connection_pool' into development

Author: kavyako

Release/include/cpprest/details/http_server_asio.h

@@ -87,7 +87,10 @@ class connection
         if (is_https)
         {
             m_ssl_context = utility::details::make_unique<boost::asio::ssl::context>(boost::asio::ssl::context::sslv23);
-            ssl_context_callback(*m_ssl_context);
+            if (ssl_context_callback)
+            {
+                ssl_context_callback(*m_ssl_context);
+            }
             m_ssl_stream = utility::details::make_unique<boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>(*m_socket, *m_ssl_context);
 
             m_ssl_stream->async_handshake(boost::asio::ssl::stream_base::server, [this](const boost::system::error_code&) { this->start_request_response(); });

Release/include/cpprest/http_client.h

@@ -100,7 +100,6 @@ class http_client_config
 #endif
         , m_set_user_nativehandle_options([](native_handle)->void{})
 #if !defined(_WIN32) && !defined(__cplusplus_winrt)
-        , m_ssl_context_callback([](boost::asio::ssl::context&)->void{})
         , m_tlsext_sni_enabled(true)
 #endif
 #if defined(_WIN32) && !defined(__cplusplus_winrt)