[ospfd] cancel OSPF timer hack in nsm_change_state

[ospfd] cancel OSPF timer hack in nsm_change_state

This piece of code causes all Quagga routers on a broadcast link to
send a HELLO packet simultaneously if they see a new neighbor. It also
resets the HELLO timer, so all the quagga routers will continue to
send HELLO packets simultaneously in the future. This is not good
(especially on networks with a lot of Quagga routers connected), and
is explicitly discouraged by the OSPF standard, RFC 2328 (chapter
4.4.Timers).

I suggest to remove the code snippet, it does not provide much benefit
anyway.