perl-net-ssh2: add missing dependency on zlib
perl-net-ssh2 requires zlib. When using the openssl backend to libssh2, this
dependency is implicit via openssl, but when using the libgcrypt backend the
dependency is missing.
Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>