bugfix: stream-typed cosockets: we did not set the "error" field of the ngx_connection_t object which MIGHT lead to socket leaks.

Author: agentzh

src/ngx_http_lua_socket_tcp.c

@@ -2876,6 +2876,7 @@ ngx_http_lua_socket_send(ngx_http_request_t *r,
     }
 
     if (n == NGX_ERROR) {
+        c->error = 1;
         u->socket_errno = ngx_socket_errno;
         ngx_http_lua_socket_handle_write_error(r, u,
                                                NGX_HTTP_LUA_SOCKET_FT_ERROR);