Monitor plugin error message in cacti log

[WirthmU]

Describe the bug Error message about monitor plugin in Cacti log

To Reproduce

23-02-2023 09:49:25 - CMDPHP PHP ERROR Backtrace: (/plugins/monitor/poller_monitor.php[87]:monitor_uptime_checker(), /plugins/monitor/poller_monitor.php[175]:explode(), CactiErrorHandler())
23-02-2023 09:49:25 - ERROR PHP DEPRECATED in Plugin 'monitor': explode(): Passing null to parameter #2 ($string) of type string is deprecated in file: /usr/share/cacti/site/plugins/monitor/poller_monitor.php on line: 175 

Expected behavior No complaints about monitor plugin in the Cacti error log

Plugin (please complete the following information):

• Version: current
• Source: cacti

Desktop (please complete the following information):

• OS: Ubuntu
• Browser Firefox