|Notice that there is no 'delete' button|
Here's the quick fix for this problem. Meanwhile I'm pretty sure people at facebook are working at some solution.
The solution is to use the mobile website of facebook. Please note that I did not say mobile app!
You have to use the Facebook's Mobile SITE.
Once you open this url, go to your page, open the image you want to delete and click on more options as shown in the image below.
And click on edit image. You will see the delete button afterwards.
Let me know your thought.