Kylian Mbappe gestures after scoring Paris Saint-Germain's first goal in a 3-1 French Cup quarterfinal victory over Nice on Wednesday. PARIS — Kylian Mbappe returned to the starting lineup and scored as Paris Saint-Germain beat Nice 3-1 in the quarterfinals of the French Cup on Wednesday. Having only been used as a substitute in last weekend's 2-2 draw with Reims …