Pointed out by @fiatjaf, and indeed it happened to me as well; a peer with
a high feerate reconnects and sends a similar (but now ludicrous) feerate,
and we get upset:
```
$ lightning-cli listpeers 039c73f53daad1050a6a72afb5353a2152f3152ee17168cd0ab28c2cb3e0050e36
{
"peers": [
{
"id": "039c73f53daad1050a6a72afb5353a2152f3152ee17168cd0ab28c2cb3e0050e36",
"connected": false,
"channels": [
{
"state": "CHANNELD_NORMAL",
"scratch_txid": "d796aa9c44920cc7169cdb61e36437bf180cedaec44103a69591ce2baac9b1d9",
"last_tx_fee": "14329000msat",
"last_tx_fee_msat": "14329000msat",
"feerate": {
"perkw": 19791,
"perkb": 79164
},
```
Then in the logs:
```
2021-07-23T19:34:56.227Z DEBUG 039c73f53daad1050a6a72afb5353a2152f3152ee17168cd0ab28c2cb3e0050e36-channeld-chan#39381: billboard perm: update_fee 17055 outside range 253-7210
```
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
7bde0ead4d