T4934: ospf: Fix inter-area route summarization

Setting something like `protocols ospf area 10 range 10.10.0.0/16` without sub options doesn't work. This is because no range commands are generated when there is no leaf nodes set under the `range` tag node.

```
edit protocols ospf
set area 16 network 10.10.0.0/16
set area 16 range 10.10.0.0/16
commit
```

```
$ vtysh -c 'show run'
!
router ospf
 auto-cost reference-bandwidth 100
 timers throttle spf 200 1000 10000
 network 10.10.0.0/16 area 16
exit
```

The generated FRR commands above is missing something like:

```
 area 16 range 10.10.0.0/16
```

0 files changed, 0 insertions, 0 deletions