Assertion failure on shutdown caused by refresh_callback()
See https://gitlab.isc.org/isc-projects/bind9/-/jobs/2212377:
D:catz:Core was generated by `/builds/isc-projects/bind9/bin/named/.libs/named -D catz-ns2 -X named.lock -m r'.
8477D:catz:Program terminated with signal SIGABRT, Aborted.
8478D:catz:#0 0x00007f267f9a684c in __pthread_kill_implementation () from /lib64/libc.so.6
8479D:catz:[Current thread is 1 (Thread 0x7f2679c73640 (LWP 31354))]
8480D:catz:#0 0x00007f267f9a684c in __pthread_kill_implementation () from /lib64/libc.so.6
8481D:catz:#1 0x00007f267f9596a6 in raise () from /lib64/libc.so.6
8482D:catz:#2 0x00007f267f9437d3 in abort () from /lib64/libc.so.6
8483D:catz:#3 0x00007f2680ac2581 in abort () from /lib64/libtsan.so.0
8484D:catz:#4 0x000000000042269e in assertion_failed (file=<optimized out>, line=<optimized out>, type=<optimized out>, cond=<optimized out>) at main.c:236
8485D:catz:#5 0x00007f26804edbf0 in isc_assertion_failed (file=file@entry=0x7f2680465225 "request.c", line=line@entry=1028, type=type@entry=isc_assertiontype_require, cond=cond@entry=0x7f26804654e0 "((request) != ((void *)0) && ((const isc__magic_t *)(request))->magic == ((('R') << 24 | ('q') << 16 | ('u') << 8 | ('!'))))") at assertions.c:47
8486D:catz:#6 0x00007f26803630ae in req_senddone (eresult=eresult@entry=ISC_R_CANCELED, region=region@entry=0x0, arg=0x7b440006a540) at request.c:1028
8487D:catz:#7 0x00007f2680244db9 in send_done (handle=0x7b4800038880, result=result@entry=ISC_R_CANCELED, cbarg=cbarg@entry=0x7b5000041600) at dispatch.c:1862
8488D:catz:#8 0x00007f26804d5df6 in isc__nm_async_sendcb (worker=worker@entry=0x7ba000009770, ev0=ev0@entry=0x7b480007da00) at netmgr/netmgr.c:2847
8489D:catz:#9 0x00007f26804d66e7 in process_netievent (worker=worker@entry=0x7ba000009770, ievent=ievent@entry=0x7b480007da00) at netmgr/netmgr.c:970
8490D:catz:#10 0x00007f26804d6abb in process_queue (worker=worker@entry=0x7ba000009770, type=type@entry=NETIEVENT_NORMAL) at netmgr/netmgr.c:1008
8491D:catz:#11 0x00007f26804d73e4 in process_all_queues (worker=0x7ba000009770) at netmgr/netmgr.c:754
8492D:catz:#12 async_cb (handle=0x7ba000009ad0) at netmgr/netmgr.c:783
8493D:catz:#13 0x00007f267fd12100 in uv__async_io (loop=0x7ba000009780, w=0x7ba000009948, events=1) at /usr/src/libuv-v1.42.0/src/unix/async.c:163
8494D:catz:#14 0x00007f267fd2e3d1 in uv__io_poll (loop=0x7ba000009780, timeout=0) at /usr/src/libuv-v1.42.0/src/unix/epoll.c:374
8495D:catz:#15 0x00007f267fd12b6c in uv_run (loop=0x7ba000009780, mode=UV_RUN_DEFAULT) at /usr/src/libuv-v1.42.0/src/unix/core.c:389
8496D:catz:#16 0x00007f26804d6c07 in nm_thread (worker0=0x7ba000009770) at netmgr/netmgr.c:689
8497D:catz:#17 0x00007f2680529b8b in isc__trampoline_run (arg=0x7b0800019be0) at trampoline.c:185
8498D:catz:#18 0x00007f2680a92550 in __tsan_thread_start_func () from /lib64/libtsan.so.0
8499D:catz:#19 0x00007f267f9a4a87 in start_thread () from /lib64/libc.so.6
8500D:catz:#20 0x00007f267fa288d4 in clone () from /lib64/libc.so.6