The compartments aren't not well resized when the node is resized in height

Steps to reproduce:

1. Create a new ClassDiagram

2. Create a Class

   Resize the Class (increase its size-> the last compartment doesn't fill all the available space.

In addition we will also get this bug with the Symbol Compartment (issue #229), with these actions:

1. Create a ClassDiagram

2. Create a Class

3. Add A symbole

4. Resize the Class (increase its size) -> the symbol compartment doesn't fill all the available space.

5. Delete the Symbol -> more useless space is displayed inside the Class