can't start JACK with real-time scheduling even when in audio group

I'm running Ubuntu 17.04. I've installed jack2 and have added myself to the 'audio' group as suggested at

  http://jackaudio.org/faq/linux_rt_config.html

But when I start JACK it reports

Tue May 23 16:10:24 2017: ERROR: Cannot use real-time scheduling (RR/10)(1: Operation not permitted)
Tue May 23 16:10:24 2017: ERROR: AcquireSelfRealTime error

I am in the 'audio' group in /etc/group:

adam:~$ grep audio /etc/group
audio:x:29:pulse,adam
adam:~$

(I restarted the machine after adding myself to this group.)

'ulimit' isn't showing real-time priority privileges for me:

adam:~$ ulimit -a | grep real
real-time priority (-r) 0
adam:~$

The file /etc/security/limits.d/audio.conf looks like this:

===

# Provided by the jackd package.
#
# Changes to this file will be preserved.
#
# If you want to enable/disable realtime permissions, run
#
# dpkg-reconfigure -p high jackd

@audio - rtprio 95
@audio - memlock unlimited
#@audio - nice -19

===