netdata: disable shared memory totals by default

Fix log spam:
daemon.err netdata[2090]: PROCFILE: Cannot open file '/proc/sysvipc/shm'
This is caused by a non existant /proc/sysvipc/shm because of the
CONFIG_PROC_STRIPPED option that is enabled by default in the kernel
generic target config

Signed-off-by: Tiago Gaspar <tiagogaspar8@gmail.com>
(cherry picked from commit 5f65d87b)