Fix WooCommerce product gallery issue

Fix: external images added in WooCommerce Product gallery disappear when clicking Publish/Update.

Similar issue of other plugins may also by chance be fixed.

Detailed information of this issue:

#10
https://wordpress.org/support/topic/product-gallery-image-not-working/

Debug warnings are fixed

v1.1.1

Update version to 1.1.1

Batch-add is supported!

Multiple URL links can be added in batch to the media library, with one URL per line in the text box.

Fixed a bug which causes HTTP 500

Fixed a bug which causes HTTP 500 – internal server error.

The error occurs in previous version when the plugin fails to get the image size and MIME type. The HTTP 500 error causes the plugin message not correctly displayed in the media upload panel. It also causes the Add External Media without Import page broken.