discovery issue in bgp-peers.inc.php

Hi Guys

there seems to be an issue on the bgp discovery in the version 19.11.10159:

PHP Fatal error: Uncaught Error: Call to undefined function get_astext() in /opt/observium/includes/discovery/bgp-peers.inc.php:397
Stack trace:
#0 /opt/observium/includes/discovery/functions.inc.php(387): include()
#1 /opt/observium/discovery.php(191): discover_device(Array, Array)
#2 {main}
thrown in /opt/observium/includes/discovery/bgp-peers.inc.php on line 397

thx