kmer2read_distr uses omp_get_num_procs() instead of omp_get_num_threads() to check the validity of the -t parameter

[smdabdoub]

https://github.com/jenniferlu717/Bracken/blob/699e89169b72c5330c64259dcbafa1a40133f3f2/src/kmer2read_distr.cpp#L170

[smdabdoub]

Although, after re-compiling with the threads function, it still complains with anything >1, and I have OMP_NUM_THREADS set correctly for building with kraken2, and it works there.