job-list: allow guests to access module stats

Problem: flux module stats is generally open to guests,
but the RPC override in the job-list module is not.

Open job-list.stats-get to guests.
Add a test to t2260-job-list.t.

Author: garlick

src/modules/job-list/job-list.c

@@ -146,7 +146,7 @@ static const struct flux_msg_handler_spec htab[] = {
     { .typemask     = FLUX_MSGTYPE_REQUEST,
       .topic_glob   = "job-list.stats-get",
       .cb           = stats_cb,
-      .rolemask     = 0
+      .rolemask     = FLUX_ROLE_USER,
     },
     { .typemask     = FLUX_MSGTYPE_EVENT,
       .topic_glob   = "job-purge-inactive",

t/t2260-job-list.t

@@ -358,6 +358,11 @@ test_expect_success 'flux job list all jobs works' '
 	test_cmp all.ids list_all_jobids.out
 '
 
+test_expect_success 'flux module stats job-list is open to guests' '
+	FLUX_HANDLE_ROLEMASK=0x2 \
+	    flux module stats job-list >/dev/null
+'
+
 # with single anonymous queue, queues arrays should be zero length
 test_expect_success 'job stats lists jobs in correct state (mix)' '
 	flux job stats | jq -e ".job_states.depend == 0" &&