openshift.ks: Don't immediately run sysctl

configure_sysctl_on_node: Delete the sysctl command to immediately load
sysctl settings.

Trying to load sysctl settings during configuration produces error messages
for settings that comes from kernel modules that are not loaded at
installation time, and we already expect the user to reboot the host anyway
to start services and put other configuration into effect after running the
installation script.
Merge pull request #84 from Miciah/openshift.ks-dont-immediately-run-sysctl

openshift.ks: Don't immediately run sysctl