workaround for conntrack_max not being set on boot

See comment #13 on the following bug:
https://bugs.launchpad.net/ubuntu/+source/procps/+bug/690433

tl;dr
conntrack module is loaded after procps service is run so, sysctl values
for conntrack never get set.

Change-Id: Ic516366357e9bb023c674921e76feca81fe51de7
Merge "workaround for conntrack_max not being set on boot"