LND fails a payment on getting `FeeInsufficient` instead of retrying it with updated fees

[akumaigorodski]

Details are outlined here: https://github.com/btcontract/lnwallet/issues/123

When getting a FeeInsufficient on sending a payment LND seems to fail it right away while I'd expect it to retry it with bumped fees.

[joostjager]

I suspect this will be fixed by #2151

[Roasbeef]

Should fix this for 0.11.

[joostjager]

I think it is probably good to wait for the in-memory graph to land.

[cfromknecht]

@Roasbeef @joostjager should we continue targeting this for 0.11?

[joostjager]

I still think that if we are going to overhaul the graph structure, it is overall cheaper to implement this afterwards.

[halseth]

The approach taken in #2151 is to just update the bandwidth hints with updated fees