ezcontentobject_link is not refreshed when relation list attribute is removed.

Steps to reproduce

Class "A" has relation list attribute "B". Create a couple objects of "A" class and set some relations into "B" attribute. Remove "B" attribute. In the "Relations" tab (ez back end) class "A" objects still have some relations.

solution: http://pastebin.com/U36MYf0z or create new version for all calss "A" objects