Files
lightning/gossipd
Rusty Russell d2cf2a3f51 gossipd: don't use connectd daemon_conn after it shuts down.
Simply exit, like we do when master daemon_conn exits.

```
Valgrind error file: valgrind-errors.2211908
==2211908== Invalid read of size 8
==2211908==    at 0x12AC13: daemon_conn_send (daemon_conn.c:137)
==2211908==    by 0x113CD9: queue_peer_msg (gossipd.c:118)
==2211908==    by 0x11B806: query_channel_range (queries.c:1169)
==2211908==    by 0x1250DD: peer_gossip_probe_scids (seeker.c:706)
==2211908==    by 0x1253B1: check_firstpeer (seeker.c:788)
==2211908==    by 0x1256CA: seeker_check (seeker.c:884)
==2211908==    by 0x1366AC: timer_expired (timeout.c:62)
==2211908==    by 0x1163D1: main (gossipd.c:1146)
==2211908==  Address 0x4cafdf0 is 48 bytes inside a block of size 88 free'd
==2211908==    at 0x48460C4: free (vg_replace_malloc.c:872)
==2211908==    by 0x1805EA: del_tree (tal.c:421)
==2211908==    by 0x1808BE: tal_free (tal.c:486)
==2211908==    by 0x12AB25: destroy_dc_from_conn (daemon_conn.c:112)
==2211908==    by 0x17FFDF: notify (tal.c:237)
==2211908==    by 0x180519: del_tree (tal.c:402)
==2211908==    by 0x1808BE: tal_free (tal.c:486)
==2211908==    by 0x16EE9A: io_close (io.c:450)
==2211908==    by 0x16ECA9: do_plan (io.c:401)
==2211908==    by 0x16ED16: io_ready (io.c:417)
==2211908==    by 0x1710B2: io_loop (poll.c:453)
==2211908==    by 0x1163C5: main (gossipd.c:1144)
==2211908==  Block was alloc'd at
==2211908==    at 0x484384F: malloc (vg_replace_malloc.c:381)
==2211908==    by 0x180064: allocate (tal.c:250)
==2211908==    by 0x180634: tal_alloc_ (tal.c:428)
==2211908==    by 0x12AB65: daemon_conn_new_ (daemon_conn.c:122)
==2211908==    by 0x1155F4: gossip_init (gossipd.c:763)
==2211908==    by 0x116014: recv_req (gossipd.c:999)
==2211908==    by 0x12A828: handle_read (daemon_conn.c:31)
==2211908==    by 0x16E09F: next_plan (io.c:59)
==2211908==    by 0x16ECD4: do_plan (io.c:407)
==2211908==    by 0x16ED16: io_ready (io.c:417)
==2211908==    by 0x1710B2: io_loop (poll.c:453)
==2211908==    by 0x1163C5: main (gossipd.c:1144)
==2211908== 
```
2022-03-23 13:20:12 +10:30
..