lightningd: correctly store our own channel_reserve_satoshis

openingd calculates our reserve based on the channel amount (even if
we're funding, to keep the calculation in one place), but it wasn't
reporting it back to the master daemon.  We initialized it to 0 so that
valgrind wouldn't get upset, as it's part of a structure we send over
the wire.

Have openingd report back, and also initialize it to an impossible value
as extra assurance.  And remove a stray (harmless but weird) semicolon.

Reported-by: Gálli Zoltán
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_lightningd.py

@@ -7,7 +7,6 @@ from utils import wait_for
 import copy
 import json
 import logging
-import pytest
 import queue
 import os
 import random
@@ -5114,7 +5113,6 @@ class LightningDTests(BaseLightningDTests):
         # fundee will also forget and disconnect from peer.
         assert len(l2.rpc.listpeers(l1.info['id'])['peers']) == 0
 
-    @pytest.mark.xfail(strict=True)
     def test_reserve_enforcement(self):
         """Channeld should disallow you spending into your reserve"""
         l1, l2 = self.connect(may_reconnect=True)
@@ -5125,6 +5123,9 @@ class LightningDTests(BaseLightningDTests):
 
         l2.stop()
 
+        # They should both aim for 1%.
+        assert l2.db_query('SELECT channel_reserve_satoshis FROM channel_configs') == [{'channel_reserve_satoshis': 10**6 // 100}, {'channel_reserve_satoshis': 10**6 // 100}]
+
         # Edit db to reduce reserve to 0 so it will try to violate it.
         l2.db_query('UPDATE channel_configs SET channel_reserve_satoshis=0',
                     use_copy=False)