It broke too: https://jenkins.tails.boum.org/job/test_Tails_ISO_stable/78/

refs: #10774

Have the security advisory against 1.7 point to 1.8.1, since 1.8 doesn't fix all issues fixed in here.

On https://jenkins.tails.boum.org/view/RM/job/test_Tails_ISO_experimental/67/
the screenshot shows that Evince did manage to open it, but the video lacks
the frames that prove it ⇒ I bet that Evince needed just a tiny bit more
than 10 seconds.

refs: #10776

refs: #10774