[1863] Make stats-httpd listen on a non-default port for lettuce tests (contd.)

tests/lettuce/configurations/default.config

@@ -6,5 +6,11 @@
             "severity": "DEBUG",
             "name": "auth"
         } ]
+    },
+    "StatsHttpd": {
+        "listen_on": [ {
+            "port": 47811,
+            "address": "127.0.0.1"
+        } ]
     }
 }