Verified the patch '2377747-96.patch' in comment #96 and the patch is working...

Verified the patch '2377747-96.patch' in comment #96 and the patch is working as expected.Appropriate error message is displayed.
The file zero.png could not be uploaded.
The image file is invalid or the image type is not allowed. Allowed types: png, jpeg, gif

Steps performed to verify the patch are as follows:
1.Reproduced the issue on local D8 site
2.Applied patch 2377747-96.patch
3.Verified if the new error message is displayed.
Attaching snapshot for reference.