*: support replace-peer-as (aka as-override)

we use the term replace-peer-as instead of as-override
since openconfig is using it.

cli

```
$ gobgp n add <neighbor-addr> as <asn> replace-peer-as
```

config

```
neighbor:
  config:
    peer-as: <asn>
    neighbor-address: <neighbor-addr>
  as-path-options:
    config:
      replace-peer-as: true
```

Signed-off-by: Wataru Ishida <ishida.wataru@lab.ntt.co.jp>

1 files changed, 1 insertions, 0 deletions

diff --git a/docs/sources/configuration.md b/docs/sources/configuration.md
index 31362524..c00b04fa 100644
--- a/docs/sources/configuration.md
+++ b/docs/sources/configuration.md
@@ -52,6 +52,7 @@
         remove-private-as = "all"
     [neighbors.as-path-options.config]
         allow-own-as = 1
+        replace-peer-as = true
     [neighbors.timers.config]
         connect-retry = 5
         hold-time = 9