[BUG] Bbox data error when preprocessing the posetrack dataset

[Timkeeper2018]

The bbox data is wrong when preprocessing the posetrack dataset, there are about 64 bbox data with errors, similar to bbox[i, :] = [-499734.75000,-499825.00000,877958.49375,1170611.32500
], the data tends to +-inf

The data is posetrack20108