ThreadSanitizer: data race bin/named/controlconf.c:257:22 in control_senddone

While this looks innocuous (it's a double write to listener->listening = true from two different threads), it also might be a manifestation of something more serious:

• c4ae392dcfa8039dec6ea9d8b889585cf1b4dac39600c33ff60ec627014e6b8e.txt