fix: remove hide_eth variable & function usage in DockerSettings.page

- Eliminated the $hide_eth variable as it was not used and attempting to be set by an undeclared function

emhttp/plugins/dynamix.docker.manager/DockerSettings.page

@@ -424,7 +424,6 @@ $port = normalize($network);
 [$range,$size]  = my_explode('/',_var($dockercfg,"DOCKER_RANGE_$port"));
 $disabled       = $subnet ? '':'disabled';
 $dhcpDisabled   = $range ? '':'disabled';
-$hide_eth       = hide_eth($network);
 ?>
 <?if ($protocol[$network] != 'ipv6' && ($network != 'wlan0' || lan_port('wlan0',true) == 1)):?>