rstp: Change transitions order.

      Without this patch some IXIA tests fail, but standard 802.1D-2004 says
      that the order in which conditions are checked when exiting a state does
      not matter.
      Where two or more exit conditions with the same level of precedence
      become TRUE simultaneously, the choice as to which exit condition causes
      the state transition to take place is arbitrary.

Signed-off-by: Daniele Venturino <daniele.venturino@m3s.it>
rstp: Set default auto-edge value to false for testing.