add libssl-dev in setup_systools.sh

guowenxue

2021-01-12 b7d1950cd1e879d14e59b1af0756acd6a80b7ff1

tools/rpi_crosstool.tar.bz2 does not exist in tree 857d7a66c250e05da4a1ead086136e4c2aec3dca