Bugfix
    * In TLS 1.3, when using a ticket for session resumption, tweak its age
      calculation on the client side. It prevents a server with more accurate
      ticket timestamps (typically timestamps in milliseconds) compared to the
      Mbed TLS ticket timestamps (in seconds) to compute a ticket age smaller
      than the age computed and transmitted by the client and thus potentially
      reject the ticket. Fix #6623.