Combine white wine, lemon juice, olive oil, salt and pepper in a small bowl. Brush the quail with this marinade and let sit for an hour. Push a metal skewer through the quail from the thigh up through the breast on each side of the bird. Place the skewered quail atop the hot grill grates, skin side down. Cook the quail for 5 minutes, then carefully flip them over and grill for another 5 minutes until an instant-read thermometer stuck into the thigh meat reads 165°.