Upstream: fixed fail_timeout and max_fails > 1.

Due to peer->checked always set since rev. c90801720a0c (1.3.0)
by round-robin and least_conn balancers (ip_hash not affected),
the code in ngx_http_upstream_free_round_robin_peer() function
incorrectly reset peer->fails too often.

Reported by Dmitry Popov,
http://mailman.nginx.org/pipermail/nginx-devel/2013-May/003720.html

src/http/modules/ngx_http_upstream_least_conn_module.c

diff --git a/src/http/modules/ngx_http_upstream_least_conn_module.c b/src/http/modules/ngx_http_upstream_least_conn_module.c
index 87c4d8d..dbef95d 100644
--- a/src/http/modules/ngx_http_upstream_least_conn_module.c
+++ b/src/http/modules/ngx_http_upstream_least_conn_module.c
@@ -282,7 +282,10 @@
     }
 
     best->current_weight -= total;
-    best->checked = now;
+
+    if (now - best->checked > best->fail_timeout) {
+        best->checked = now;
+    }
 
     pc->sockaddr = best->sockaddr;
     pc->socklen = best->socklen;

src/http/ngx_http_upstream_round_robin.c

diff --git a/src/http/ngx_http_upstream_round_robin.c b/src/http/ngx_http_upstream_round_robin.c
index d786ed1..e0c6c58 100644
--- a/src/http/ngx_http_upstream_round_robin.c
+++ b/src/http/ngx_http_upstream_round_robin.c
@@ -523,7 +523,10 @@
     rrp->tried[n] |= m;
 
     best->current_weight -= total;
-    best->checked = now;
+
+    if (now - best->checked > best->fail_timeout) {
+        best->checked = now;
+    }
 
     return best;
 }