“Uninitialized string offset” PHP Warning (3.7.0)

Hi,

there are a lot of the same warnings in our log, looks like a missing sanity check:

PHP Warning: Uninitialized string offset 0 in /…/plugins/dhl-for-woocommerce/includes/REST_API/Parcel_DE/Item_Info.php on line 309

Link for 3.7.0: https://plugins.trac.ww.wp.xz.cn/browser/dhl-for-woocommerce/tags/3.7.0/includes/REST_API/Parcel_DE/Item_Info.php#L309

Would be great if we could get rid of those 🙂

Thanks!