Fixes in the quagga_gen_as_network.pl script for current bgp output

The script in the current form dind't work with output like this:

    *>i1.0.0.0/24       193.149.123.15             0    100      0 15659 i
    *>i1.0.4.0/22       149.6.150.210       165090    100      0 125 7545 56212 i

Because it was using spaces to separate the content and only worked when there weren't the 'i' characters

    *> 1.0.0.0/24       193.149.123.15             0    100      0 15659 i
    *> 1.0.4.0/22       149.6.150.210       165090    100      0 125 7545 56212 i