Remove control-use-cert. It is ignored for local sockets (since unbound 1.7.3).

OK florian@ sthen@

src/etc/unbound.conf

@@ -1,4 +1,4 @@
-# $OpenBSD: unbound.conf,v 1.13 2018/12/12 23:20:38 sthen Exp $
+# $OpenBSD: unbound.conf,v 1.14 2018/12/16 20:41:30 tim Exp $
 
 server:
 	interface: 127.0.0.1
@@ -50,7 +50,6 @@ server:
 
 remote-control:
 	control-enable: yes
-	control-use-cert: no
 	control-interface: /var/run/unbound.sock
 
 # Use an upstream forwarder (recursive resolver) for some or all zones.