A typo in TrackBase.h

[zhuqingzhang]

In the function of set_calibration of Class TrackBase, there is a typo I guess. In the 107th line,

if(mtx_feeds.empty() || camera_k_OPENCV.empty() || camera_k_OPENCV.empty() || this->camera_fisheye.empty())

there are two "camera_k_OPENCV.empty()", and I assume one of these should be "camera_d_OPENCV.empty()", although it should not effect the performance of code.

[goldbattle]

Thanks for the correction!

[goldbattle]

Addressed in #117.