Stream: reshuffled ngx_stream_listen_opt_t fields.

In preparation for adding more parameters to the listen directive,
and to be in sync with the corresponding structure in the http module.
No functional changes.

src/stream/ngx_stream.h

@@ -56,18 +56,19 @@ typedef struct {
     unsigned                       reuseport:1;
     unsigned                       so_keepalive:2;
     unsigned                       proxy_protocol:1;
-#if (NGX_HAVE_KEEPALIVE_TUNABLE)
-    int                            tcp_keepidle;
-    int                            tcp_keepintvl;
-    int                            tcp_keepcnt;
-#endif
+
     int                            backlog;
     int                            rcvbuf;
     int                            sndbuf;
+    int                            type;
 #if (NGX_HAVE_TCP_FASTOPEN)
     int                            fastopen;
 #endif
-    int                            type;
+#if (NGX_HAVE_KEEPALIVE_TUNABLE)
+    int                            tcp_keepidle;
+    int                            tcp_keepintvl;
+    int                            tcp_keepcnt;
+#endif
 } ngx_stream_listen_opt_t;