Since
753ad2390bfbc90f6bc1b68f980ef4bcdc2cfddc ZoneToCache checks
whether a given zone has a recursive forward rule, so we need the
Domain map to be properly initialized in all tests, as they can be
executed in random order.
Fixes:
```
ThreadSanitizer:DEADLYSIGNAL
==35969==ERROR: ThreadSanitizer: SEGV on unknown address 0x000000000018 (pc 0x5568e9f8bb04 bp 0x4c00000000000 sp 0x7ffcc13b77f0 T35969)
==35969==The signal is caused by a READ memory access.
==35969==Hint: address points to the zero page.
#0 std::_Hashtable<DNSName, std::pair<DNSName const, SyncRes::AuthDomain>, std::allocator<std::pair<DNSName const, SyncRes::AuthDomain> >, std::__detail::_Select1st, std::equal_to<DNSName>, std::hash<DNSName>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::empty() const /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/hashtable.h:653:23 (testrunner+0x47fb04)
#1 std::unordered_map<DNSName, SyncRes::AuthDomain, std::hash<DNSName>, std::equal_to<DNSName>, std::allocator<std::pair<DNSName const, SyncRes::AuthDomain> > >::empty() const /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/unordered_map.h:306:21 (testrunner+0x47fb04)
#2 SyncRes::getBestAuthZone(DNSName*) /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/syncres.cc:2464:29 (testrunner+0x47fb04)
#3 SyncRes::isRecursiveForward(DNSName const&) /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/syncres.cc:1098:21 (testrunner+0x47fb04)
#4 ZoneData::ZoneToCache(RecZoneToCache::Config const&) /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/rec-zonetocache.cc:423:28 (testrunner+0x404931)
#5 RecZoneToCache::ZoneToCache(RecZoneToCache::Config const&, RecZoneToCache::State&) /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/rec-zonetocache.cc:473:10 (testrunner+0x4059fd)
#6 rec_zonetocache::zonemdGenericTest(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, pdns::ZoneMD::Config, pdns::ZoneMD::Config, unsigned long) /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/test-rec-zonetocache.cc:157:3 (testrunner+0x7a7113)
#7 rec_zonetocache::test_zonetocachegeneric::test_method() /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/test-rec-zonetocache.cc:177:3 (testrunner+0x7a60a5)
#8 rec_zonetocache::test_zonetocachegeneric_invoker() /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/test-rec-zonetocache.cc:173:1 (testrunner+0x7a60a5)
#9 boost::detail::function::void_function_invoker0<void (*)(), void>::invoke(boost::detail::function::function_buffer&) /usr/include/boost/function/function_template.hpp:117:11 (testrunner+0x57dfab)
#10 <null> <null> (libboost_unit_test_framework.so.1.74.0+0x323fd)
#11 boost::execution_monitor::catch_signals(boost::function<int ()> const&) <null> (libboost_unit_test_framework.so.1.74.0+0x30b0c)
#12 boost::execution_monitor::execute(boost::function<int ()> const&) <null> (libboost_unit_test_framework.so.1.74.0+0x30b90)
#13 boost::execution_monitor::vexecute(boost::function<void ()> const&) <null> (libboost_unit_test_framework.so.1.74.0+0x30c60)
#14 boost::unit_test::unit_test_monitor_t::execute_and_translate(boost::function<void ()> const&, unsigned long) <null> (libboost_unit_test_framework.so.1.74.0+0x5f1a0)
#15 <null> <null> (libboost_unit_test_framework.so.1.74.0+0x37cdf)
#16 <null> <null> (libboost_unit_test_framework.so.1.74.0+0x381d0)
#17 <null> <null> (libboost_unit_test_framework.so.1.74.0+0x381d0)
#18 boost::unit_test::framework::run(unsigned long, bool) <null> (libboost_unit_test_framework.so.1.74.0+0x3bf36)
#19 boost::unit_test::unit_test_main(bool (*)(), int, char**) <null> (libboost_unit_test_framework.so.1.74.0+0x5e10d)
#20 main /__w/pdns/pdns/pdns/recursordist/pdns-recursor-0.0.0-git1/testrunner.cc:84:10 (testrunner+0xc85591)
#21 <null> <null> (libc.so.6+0x27249)
#22 __libc_start_main <null> (libc.so.6+0x27304)
#23 _start <null> (testrunner+0x1b79e0)
```
Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>