Removed manual initialization of flashfocus from xinitrc, enabled the
service in systemd.
Changed the restart timer to 5 seconds, to mirror other X-dependent user
services to circumvent systemd being too eager to start the service
before X is ready on booting.
Both greenclip and redshift did not automatically start on system start,
since they needed X to be running but their restart was almost
instantaneously. So, they restarted their alloted 5 times before X was
ready and gave up.
Restart time has been set to 5 and 10 seconds, so their startup takes a
little longer but should, in most cases, succeed.