fix forward declaration of struct TntConfig (produced a compiler warning)
fix forward declaration of struct TntConfig (produced a compiler warning)

maekitalo/tntnet,maekitalo/tntnet,OlafRadicke/tntnet,maekitalo/tntnet,OlafRadicke/tntnet,maekitalo/tntnet,maekitalo/tntnet,maekitalo/tntnet,OlafRadicke/tntnet,OlafRadicke/tntnet,OlafRadicke/tntnet