The order of ezobjectlist is not updated when you remove one or more objects

Steps to Reproduce

1. Alter Article class and add an Object relations attribute
2. Create four file content objects: file_001, file_002, file_003, file_004
3. Create article_001 and add the four file objects into the Object relations attribute
4. Confirm that each object has the correct order number. If you upload in sequence, file_001 should have order 1, file_002 should have order 2, and so on.
5. Publish the article
6. Now, go to the backend and delete (do not sent to trash) file_003
7. Edit article_001 and look at Object relations attribute
8. file_001 has order 1, file_002 has order 2, but file_004 still has order 4

If you have 4 objects:
object 1 - sort order 1
object 2 - sort order 2
object 3 - sort order 3
object 4 - sort order 4

delete object 3, and you are left with

object 1 - sort order 1
object 2 - sort order 2
object 4 - sort order 4 (the expected sort order is 3)