Description:
------------
I am not entirely certain this is a "bug" per se, but think it is at least not functioning the way it should...

when modifying a value in ldap that is inherently a number (like a phone number), it throws the error:  ldap_modify_batch(): Each element of a 'values' array must be a string.

Though I understand that this is by-design... I feel that the 'value' passed should be a 'scalar', not explicitly a string...  i.e. it did not seem intuitive that I should have to cast the number to string first: (e.g.  $value . '').

There may not be a reasonable way to fix this however, as there is no IS_SCALAR in zend_types (rightly so... as we are talking about C data types, not php data types in this context).  Given the nature of the issue, I think the easiest fix would be in https://github.com/php/php-src/blob/master/ext/ldap/ldap.c line 2704, by adding a check for IS_(LONG|DOUBLE) and performing an snprintf on it, and that just may not be worth it... I leave it to you.

thanks

Test script:
---------------
ldap_modify_batch($connection, $dn, [
    'attrib'  => 'mobile',
    'modtype' => LDAP_MODIFY_BATCH_ADD,
    'values'  => [ 1234567 ]
]);