hmm it seems it's grabbed by debian repository (binary or source) if you have libss1 installed then do : ln -s /usr/lib/libss.so.1.0.0 /usr/lib/libssl1.so.1.0.0 not sure as i have hydra installed on easy-debian
sudo apt-get install libssh libmysqlclient libpq libssl pkg-config libgtk2.0