bootflags: fix for bootflags not applied to local kickstart kernel

rocks set host bootflags were not applied to kernel boot parameters
when using local node kickstart kernel.

See:
https://lists.sdsc.edu/pipermail/npaci-rocks-discussion/2012-July/058586.html

Reported-by: Cavanaugh, Sean <sean.cavanaugh@usask.ca>
Reported-by: Andres <nac1982@yahoo.com.ar>
base: fix network setting for proper reverse path filtering

in Centos6.x they changed the behavior of
net.ipv4.conf.default.rp_filter=1 (which is set in /etc/sysctl.conf)
and it will disable assimetri routing.
To restore Centos5 behavior net.ipv4.conf.default.rp_filter must
be set to 2.

ref: https://access.redhat.com/site/solutions/53031