Update mkl-dnn version for building from source

When building from source with CMake, the compilation of mkl-dnn fails with gcc-8 because the version used in 3rdparty is too old. A bugfix for mkl-dnn was made recently (see https://github.com/intel/mkl-dnn/issues/283) and should solve the issue.
Thanks