[sonic-quagga]: Fix ipv6 nexthop ifindex.

[pavel-shirshov]

- Why I did it
sonic-quagga repository has new fix. Update submodule to bring the fix into the image.

- How I did it
git submodule update --remote ...

- How to verify it
Build an image. Run on your dut. Check the situation when:

1. You have lo interfaces with address x.x.x.x
2. You have a dynamic session which uses x.x.x.x as a source address
3. You have a ipv6 prefix updates through this session to the device.
4. Check that the sessions nexthop interface is not equal to 'lo' interface, and point to correct nexthop interface.
   - Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)