~/.rsync-backup.sh: Exit if another rsync is already running.

.rsync-backup.sh

# rsync's $HOME to my local backup server.
# Exit if already running
if `pidof rsync &> /dev/null`; then
	echo "Looks like another rsync is already running, exiting..."
	exit 0
fi
# Check whether I'm at home (yeah, I know...)
ping -c1 192.168.220.109 &> /dev/null
if [ $? != 0 ]; then