By THÉRÈSE MARGOLIS When most people think of Spanish wines, they imagine a crisp Crianza from Rioja, a silky Godello from Galicia, or maybe even a sparkling Cava from Penedès. Indeed, Spain is the world’s third-largest wine producer, with thousands of varieties of robust red, fruity whites and floral rosés. But then is there that other Spanish wine, that fortified,