Use strip instead of chop in openblas_get_config()

As of https://github.com/xianyi/OpenBLAS/commit/552119c48429c76a701600d05d3a1f472a41c65c, OpenBLAS now returns the processor family at the end of the config string (yay!), without a trailing whitespace. Using strip makes this compatible with both new and old versions of OpenBLAS.