[fix] Fix first frame index at pcap opening

When opening a pcap file, it was starting at frame index 1

When running backwards, data were present and correctly parsed at frame 0

This behavior is fixed so that it now starts at frame 0 (same behavior as Veloview)

This is relative to issue #22

Reference to commit ID on Veloview side VeloView-Velodyne!133 (d86f65d2) From MR VeloView-Velodyne!133 (d86f65d2)

Note: a fix in the LidarReader would be a more suitable long term solution