soup: drop --local from postgres.telegraf_users reconcile

The manager's /etc/salt/minion (written by so-functions:configure_minion)
has no file_roots, so salt-call --local falls back to Salt's default
/srv/salt and fails with "No matching sls found for 'postgres.telegraf_users'
in env 'base'". || true was silently swallowing the error, which meant the
DB roles for the pillar entries just populated by the so-telegraf-cred
backfill loop never actually got created.

Route through salt-master instead; its file_roots already points at the
default/local salt trees.

salt/manager/tools/sbin/soup

@@ -536,7 +536,10 @@ post_to_3.1.0() {
     [[ -n "$mid" ]] || continue
     /usr/sbin/so-telegraf-cred add "$mid" || echo "  warning: so-telegraf-cred add $mid failed" >&2
   done
-  salt-call --local state.apply postgres.telegraf_users queue=True || true
+  # Run through the master (not --local) so state compilation uses the
+  # master's configured file_roots; the manager's /etc/salt/minion has no
+  # file_roots of its own and --local would fail with "No matching sls found".
+  salt-call state.apply postgres.telegraf_users queue=True || true
 
   POSTVERSION=3.1.0
 }