[BUG] proxy: stats frontend and peers were missing many initializers

This was revealed with one of the very latest patches which caused
the listener_queue not to be initialized on the stats socket frontend.
And in fact a number of other ones were missing too. This is getting so
boring that now we'll always make use of the same function to initialize
any proxy. Doing so has even saved about 500 bytes on the binary due to
the avoided code redundancy.

No backport is needed.
diff --git a/src/proxy.c b/src/proxy.c
index 7c22a75..3b56c86 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -403,6 +403,35 @@
 	return 0;
 }
 
+/* Perform the most basic initialization of a proxy :
+ * memset(), list_init(*), reset_timeouts(*).
+ * Any new proxy should be initialized via this function.
+ */
+void init_new_proxy(struct proxy *p)
+{
+	memset(p, 0, sizeof(struct proxy));
+	LIST_INIT(&p->pendconns);
+	LIST_INIT(&p->acl);
+	LIST_INIT(&p->http_req_rules);
+	LIST_INIT(&p->block_cond);
+	LIST_INIT(&p->redirect_rules);
+	LIST_INIT(&p->mon_fail_cond);
+	LIST_INIT(&p->switching_rules);
+	LIST_INIT(&p->persist_rules);
+	LIST_INIT(&p->sticking_rules);
+	LIST_INIT(&p->storersp_rules);
+	LIST_INIT(&p->tcp_req.inspect_rules);
+	LIST_INIT(&p->tcp_rep.inspect_rules);
+	LIST_INIT(&p->tcp_req.l4_rules);
+	LIST_INIT(&p->req_add);
+	LIST_INIT(&p->rsp_add);
+	LIST_INIT(&p->listener_queue);
+
+	/* Timeouts are defined as -1 */
+	proxy_reset_timeouts(p);
+	p->tcp_rep.inspect_delay = TICK_ETERNITY;
+}
+
 /*
  * This function creates all proxy sockets. It should be done very early,
  * typically before privileges are dropped. The sockets will be registered