libssh: upgrade 0.8.8 -> 0.8.9
This is a security release.
See changelog https://www.libssh.org/2020/04/09/libssh-0-9-4-and-libssh-0-8-9-security-release/
Signed-off-by: Pierre-Jean Texier <pjtexier@koncepto.io>
Signed-off-by: Khem Raj <raj.khem@gmail.com>