When setting an object relation list attribute to 'Required', it is still possible to create new content objects without specifying any related objects.

Steps to reproduce

1. Create a new content type/class
   1. Add 2 datatypes : one text line and one object relations datatype
   2. Make both fields required
2. Create a new content object of this type.
   1. fill only the text line attribute.
   2. Publish the object.