When we remove and arc having a restriction and the undo it, the restriction is not recovered.
I marked as resolved the wrong bug. This still not resolved
Issue #138 was marked as a duplicate of this issue.
In the method 'doEdit' of the class 'RemoveLinkEdit' of the package org.openmarkov.core.action, the removed link was trying to be stored in a variable after actually being deleted. This piece of code has been swapped.