security_AccountsBaseline: add cups to lp group

We want cupsd to be able to access USB printers, which will have
group:lp.

CQ-DEPEND=CL:350771
BUG=chromium:616866
TEST=security_AccountsBaseline on trybot

Change-Id: I873088ad525fadfb637874e993bae5992ba923e6
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/350850
diff --git a/client/site_tests/security_AccountsBaseline/baseline.group b/client/site_tests/security_AccountsBaseline/baseline.group
index 3de5213..9228a47 100644
--- a/client/site_tests/security_AccountsBaseline/baseline.group
+++ b/client/site_tests/security_AccountsBaseline/baseline.group
@@ -4,7 +4,7 @@
 sys:!:3:root,bin,adm
 adm:!:4:root,adm,daemon
 disk:!:6:root,adm
-lp:!:7:lp
+lp:!:7:lp,cups
 mem:!:8:
 kmem:!:9:
 wheel:!:10:root