Remove explanation about "sizelimit exceeded"

[blizzz]

even stated in the php docs: http://php.net/manual/en/function.ldap-search.php

Some directory server hosts will be configured to return no more than a preset number of entries. If this occurs, the server will indicate that it has only returned a partial results set. This also occurs if you use this parameter to limit the count of fetched entries.

[blizzz]

actually… if we would wrap the error handler in ldap, we could throw this away.

EDIT:nextcloud/server#12292 – if this is merged, we should scrap this section instead :)

[MorrisJobke]

EDIT:nextcloud/server#12292 – if this is merged, we should scrap this section instead :)

Done and I updated this PR to remove the section.