Verified the issue on Chrome and Firefox with the patch "placeholder-for-empt...

Verified the issue on Chrome and Firefox with the patch "placeholder-for-empty-caption-2563505-4.patch".
'Enter caption here' label is now visible for the image

Steps performed:
1.Create a CT Article
2.Click on Image ckeditor button
3.Select the checkbox 'caption'
4.Click Save to insert the image
5.Verify the label 'Enter caption here' is displayed

Attached snapshots for reference