notify unit test segfaults when compiled with ThreadSanitizer
[==========] Running 1 test(s).
[ RUN ] notify_start
netmgr.c:981: REQUIRE((__builtin_expect(!!((handle) != ((void*)0)), 1) && __builtin_expect(!!(((const isc__magic_t *)(handle))->magic == ((('N') << 24 | ('M') << 16 | ('H') << 8 | ('D')))), 1))) failed, back trace
#0 0x1010674ff in ??
#1 0x10106745e in ??
#2 0x101088ecc in ??
#3 0x100d504a5 in ??
#4 0x100d2959f in ??
#5 0x1014b8a6f in ??
#6 0x1014b6f58 in ??
#7 0x100d2931c in ??
#8 0x7fff66a7e2e5 in ??
Abort trap: 6