Core: removed post_accept_timeout.

Keeping post_accept_timeout in ngx_listening_t is no longer needed since
we've switched to 1 second timeout for deferred accept in 5541:fdb67cfc957d.

Further, using it in HTTP code can result in client_header_timeout being
used from an incorrect server block, notably if address-specific virtual
servers are used along with a wildcard listening socket, or if we've switched
to a different server block based on SNI in SSL handshake.
diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index ad6556d..9d8ac46 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -45,8 +45,6 @@
     size_t              pool_size;
     /* should be here because of the AcceptEx() preread */
     size_t              post_accept_buffer_size;
-    /* should be here because of the deferred accept */
-    ngx_msec_t          post_accept_timeout;
 
     ngx_listening_t    *previous;
     ngx_connection_t   *connection;
diff --git a/src/http/ngx_http.c b/src/http/ngx_http.c
index a35e9bb..e1d3d00 100644
--- a/src/http/ngx_http.c
+++ b/src/http/ngx_http.c
@@ -1714,7 +1714,6 @@
 
     cscf = addr->default_server;
     ls->pool_size = cscf->connection_pool_size;
-    ls->post_accept_timeout = cscf->client_header_timeout;
 
     clcf = cscf->ctx->loc_conf[ngx_http_core_module.ctx_index];
 
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index d453b8a..68d81e9 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -206,16 +206,17 @@
 void
 ngx_http_init_connection(ngx_connection_t *c)
 {
-    ngx_uint_t              i;
-    ngx_event_t            *rev;
-    struct sockaddr_in     *sin;
-    ngx_http_port_t        *port;
-    ngx_http_in_addr_t     *addr;
-    ngx_http_log_ctx_t     *ctx;
-    ngx_http_connection_t  *hc;
+    ngx_uint_t                 i;
+    ngx_event_t               *rev;
+    struct sockaddr_in        *sin;
+    ngx_http_port_t           *port;
+    ngx_http_in_addr_t        *addr;
+    ngx_http_log_ctx_t        *ctx;
+    ngx_http_connection_t     *hc;
+    ngx_http_core_srv_conf_t  *cscf;
 #if (NGX_HAVE_INET6)
-    struct sockaddr_in6    *sin6;
-    ngx_http_in6_addr_t    *addr6;
+    struct sockaddr_in6       *sin6;
+    ngx_http_in6_addr_t       *addr6;
 #endif
 
     hc = ngx_pcalloc(c->pool, sizeof(ngx_http_connection_t));
@@ -361,7 +362,9 @@
         return;
     }
 
-    ngx_add_timer(rev, c->listening->post_accept_timeout);
+    cscf = ngx_http_get_module_srv_conf(hc->conf_ctx, ngx_http_core_module);
+
+    ngx_add_timer(rev, cscf->client_header_timeout);
     ngx_reusable_connection(c, 1);
 
     if (ngx_handle_read_event(rev, 0) != NGX_OK) {
@@ -431,7 +434,7 @@
     if (n == NGX_AGAIN) {
 
         if (!rev->timer_set) {
-            ngx_add_timer(rev, c->listening->post_accept_timeout);
+            ngx_add_timer(rev, cscf->client_header_timeout);
             ngx_reusable_connection(c, 1);
         }
 
@@ -649,6 +652,7 @@
     ngx_http_connection_t     *hc;
     ngx_http_ssl_srv_conf_t   *sscf;
     ngx_http_core_loc_conf_t  *clcf;
+    ngx_http_core_srv_conf_t  *cscf;
 
     c = rev->data;
     hc = c->data;
@@ -680,7 +684,9 @@
             rev->ready = 0;
 
             if (!rev->timer_set) {
-                ngx_add_timer(rev, c->listening->post_accept_timeout);
+                cscf = ngx_http_get_module_srv_conf(hc->conf_ctx,
+                                                    ngx_http_core_module);
+                ngx_add_timer(rev, cscf->client_header_timeout);
                 ngx_reusable_connection(c, 1);
             }
 
@@ -755,7 +761,9 @@
             if (rc == NGX_AGAIN) {
 
                 if (!rev->timer_set) {
-                    ngx_add_timer(rev, c->listening->post_accept_timeout);
+                    cscf = ngx_http_get_module_srv_conf(hc->conf_ctx,
+                                                        ngx_http_core_module);
+                    ngx_add_timer(rev, cscf->client_header_timeout);
                 }
 
                 c->ssl->handler = ngx_http_ssl_handshake_handler;