Low: IPaddr2: Remove stray backslash

Fixes this warning (which gets logged on every recurring monitor for a
Pacemaker resource):

$ OCF_ROOT=/usr/lib/ocf OCF_RESKEY_ip=192.168.22.41 \

/usr/lib/ocf/resource.d/heartbeat/IPaddr2 monitor

grep: warning: stray \ before white space

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>