Fix issue #2
Fix issue #2

bird already provides information iff a protocol is up or not. Lets use them instead of flawky protocol state. The protocol state machine is described in the bird source code: https://github.com/BIRD/bird/blob/7a855725f2ffde508da0c7ee01dc1bcd6e0a5d93/nest/protocol.h#L290 (line 290 in nest/protocol.h currently). Therefore, only "up" should be considered safe.
czerwonk/bird_exporter