bgpd: When specifying listen address for bgpd we shouldn't imply no fib flag

bgpd: When specifying listen address for bgpd we shouldn't imply no fib flag

When `-l` is used, then no routes are exported to the kernel.

```
$ grep bgpd_options /etc/frr/daemons
bgpd_options="   -A 127.0.0.1 -l 127.0.0.2"
```

Before:

```
donatas-pc# sh run | include no-rib
bgp no-rib
donatas-pc#
```

After:

```
donatas-pc# sh run | include no-rib
donatas-pc#
```

Signed-off-by: Kris Shannon <k.shannon@amaze.com.au>
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>