tools: fix missing remote-as configuration when reload

tools: fix missing remote-as configuration when reload

From commit `411d1a2`, `bgp_delete_nbr_remote_as_line()` is added to
remove some specific bgp neighbors.  But, when reloading the following
configuration, it will wrongly remove some good ones:
`neighbor 66.66.66.6 remote-as internal`:

```
router bgp 66
 bgp router-id 172.16.204.6
 neighbor ANLAN peer-group
 neighbor ANLAN remote-as internal
 neighbor 66.66.66.6 remote-as internal <- LOST
 neighbor 66.66.66.60 peer-group ANLAN
```

The reason is that "66.66.66.6" is included in "66.66.66.60" literally,
then it is mistakenly thought to be a match.  Just fix it with
excat match.

Signed-off-by: anlan_cs <vic.lan@pica8.com>
(cherry picked from commit a70895e83ae49b15f13e0801e0743d788b0cb595)