Old constraints are always kept even after explicitly removing them

When re-clustering (with constraints) on a result with pre-existing constraints, the constraints persist even after loading them (Load old constraint) and removing them explicitly.

There should be a way to remove old constraints :

• Option 1 : Remove old constraints by default, require the user to load them explicitly if they wish to retain them.
• Option 2 : Keep old constraints by default, allow the user to remove them explicitly if they choose not to retain them.