LdapConnection#prepareNewConnection(): don't pass the port to ldap_connect()

This is deprecated since PHP 8.3.
But this is unnecessary anyway as the passed hostname is computed
by #normalizeHostname() which takes the port into account.

library/Icinga/Protocol/Ldap/LdapConnection.php

@@ -1198,7 +1198,7 @@ class LdapConnection implements Selectable, Inspectable
 
         $hostname = $this->normalizeHostname($this->hostname);
 
-        $ds = ldap_connect($hostname, $this->port);
+        $ds = ldap_connect($hostname);
 
         // Set a proper timeout for each connection
         ldap_set_option($ds, LDAP_OPT_NETWORK_TIMEOUT, $this->timeout);