Update to 7-Zip Version 21.04

- first test... no release!!!

CPP/7zip/Archive/Tar/TarHandler.cpp

@@ -763,6 +763,9 @@ STDMETHODIMP CHandler::SetProperties(const wchar_t * const *names, const PROPVAR
       _forceCodePage = true;
       _curCodePage = _specifiedCodePage = cp;
     }
+    else if (name.IsPrefixedBy_Ascii_NoCase("mt"))
+    {
+    }
     else
       return E_INVALIDARG;
   }