#1 bug in hybrid when changing behaviour

[Davide Morelli]

a leaf won't connect to another superpeer once connection to it's super is lost.
to reproduce the behaviour:
1) start the HybridExample project
2) create 3 peers: A, B and C. A will be conneted to B, B to A and C and C to B.
3) change behaviour of C (make it leaf)
4) change behaviour of B (make it leaf)
B will correctly close the connections with its leaf nodes.
C won't connect to A (but it should).