GitLab

* Update c_api LGBM_SampleIndices() comment.

rand.Sample() now returns exactly given number of samples, thus the
comment should be fixed.

* Update include/LightGBM/c_api.h
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>