Parallel problem during BKT building

[RioMichael]

Inside the KmeansAssign function during the BKT building stage, it seems like it tries to parallel the job amount the threads (if set the NumberOfThreads to more than 1)

However, as the omp_get_num_threads() would only return 1 outside the "omp parallel for" loop, the function actually never parallel the job.
I'm not sure if this is done on purpose (since the BKT build wouldn't take much time, so no need to parallel?) or just a small bug.
I've also tried to use omp_get_max_thread() instead of omp_get_num_threads() to make use of the parallel. However, there is some kind of a bug that would just end the build process without any error message.