Upstream: fixed broken connection check with eventport.

For connection close to be reported with eventport on Solaris,
ngx_handle_read_event() needs to be called.
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index a01784a..bd1627c 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -607,6 +607,12 @@
     u->store = u->conf->store;
 
     if (!u->store && !r->post_action && !u->conf->ignore_client_abort) {
+
+        if (ngx_handle_read_event(r->connection->read, 0) != NGX_OK) {
+            ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
         r->read_event_handler = ngx_http_upstream_rd_check_broken_connection;
         r->write_event_handler = ngx_http_upstream_wr_check_broken_connection;
     }