bcli: become less aggressive with onchain fee levels.

Users are more upset recently with the cost of unilateral closes
than they are the risk of being cheated.  While we complete our
anchor implementation so we can use low fees there, let's
get less aggressive (we already have 34 or 18 blocks to close
in the worst case).

The changes are:

- Commit transactions were "2 CONSERVATIVE" now "6 ECONOMICAL".
- HTLC resolution txs were "3 CONSERVATIVE" now "6 ECONOMICAL".
- Penalty txs were "3 CONSERVATIVE" now "12 ECONOMICAL".
- Normal txs were "4 ECONOMICAL" now "12 ECONOMICAL".

There can be no perfect levels, but we have had understandable
complaints recently about how high our default fee levels are.

Changelog-Changed: Protocol: channel feerates reduced to bitcoind's "6 block ECONOMICAL" rate.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_connection.py

@@ -1969,7 +1969,7 @@ def test_update_fee(node_factory, bitcoind):
     # Make payments.
     l1.pay(l2, 200000000)
     # First payment causes fee update.
-    l2.daemon.wait_for_log('peer updated fee to 14000')
+    l2.daemon.wait_for_log('peer updated fee to 11000')
     l2.pay(l1, 100000000)
 
     # Now shutdown cleanly.
@@ -2049,7 +2049,7 @@ def test_fee_limits(node_factory, bitcoind):
 
     # Try stupid high fees
     l1.stop()
-    l1.set_feerates((15000 * 10, 11000, 7500, 3750), False)
+    l1.set_feerates((15000, 11000 * 10, 7500, 3750), False)
     l1.start()
 
     l3.daemon.wait_for_log('peer_in WIRE_UPDATE_FEE')
@@ -2892,7 +2892,7 @@ def test_feerate_spam(node_factory, chainparams):
     l1.pay(l2, 10**9 - slack)
 
     # It will send this once (may have happened before line_graph's wait)
-    wait_for(lambda: l1.daemon.is_in_log('Setting REMOTE feerate to 15000'))
+    wait_for(lambda: l1.daemon.is_in_log('Setting REMOTE feerate to 11000'))
     wait_for(lambda: l1.daemon.is_in_log('peer_out WIRE_UPDATE_FEE'))
 
     # Now change feerates to something l1 can't afford.