How I can fix-it this message error:
Failed to fetch http://apt.insynchq.com/mint/dists/sarah/InRelease As seguintes assinaturas eram inválidas: KEYEXPIRED 1473479811 KEYEXPIRED 1473479811 KEYEXPIRED 1473479811 KEYEXPIRED 1473479811 KEYEXPIRED 1473479811 KEYEXPIRED 1473479811 KEYEXPIRED 1473479811
Thanks!