Fix a problem with a false assumption previously made on length of
the first field in output of a command show bgp ipv4/6 unicast neighbor
<IP> received-routes. On newer IOSes it is 5-chars long (because of RPKI flags)
but on older ones it is only 4 chars.

Example:

marge>sh bgp ipv4 uni neigh 91.210.16.3 received-r
BGP table version is 55601421, local router ID is 217.31.48.123
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *   192.88.99.0      91.210.16.3                            0 25192 i
 *   193.17.47.0      91.210.16.3                            0 25192 20701 i
^^^^^

Thanks to julianeble@yahoo.com.br for pointing it out.