pkg/asset/installconfig/ssh: Fix OPENSHIFT_INSTALL_SSH_PUB_KEY injection
pkg/asset/installconfig/ssh: Fix OPENSHIFT_INSTALL_SSH_PUB_KEY injection

Fixes the public key in OPENSHIFT_INSTALL_SSH_PUB_KEY_PATH would be read, but
an empty byte array would be returned.

derekhiggins/installer,derekhiggins/installer