Don't mess with X-forwarded-for on restarts.

Fixes: #758



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5113 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/default.vcl

@@ -40,12 +40,14 @@
  */
 
 sub vcl_recv {
+    if (req.restarts == 0) {
 	if (req.http.x-forwarded-for) {
 	    set req.http.X-Forwarded-For =
 		req.http.X-Forwarded-For ", " client.ip;
 	} else {
 	    set req.http.X-Forwarded-For = client.ip;
 	}
+    }
     if (req.request != "GET" &&
       req.request != "HEAD" &&
       req.request != "PUT" &&