start work on webconsole with templates

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd_webconsole/nlohmann/detail/meta/void_t.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace nlohmann
+{
+namespace detail
+{
+template<typename ...Ts> struct make_void
+{
+    using type = void;
+};
+template<typename ...Ts> using void_t = typename make_void<Ts...>::type;
+} // namespace detail
+}  // namespace nlohmann