bump diego-ssh
bump diego-ssh

Submodule src/github.com/cloudfoundry-incubator/diego-ssh 8e783ca..d7edb85:
  > Wait for command to start before closing stdin

Signed-off-by: Andrew Edgar <cc1cbeb507c6357651b55d7c7887132c42e42341@ca.ibm.com>

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release