message: tests: don't export in6addr_loopback
  Don't export `in6addr_loopback` because that upsets
  `contrib/devtools/symbol-check.py`
  Fixes
diff: @@ -452,17 +452,17 @@ BOOST_AUTO_TEST_CASE(netbase_dont_resolve_strings_with_embedded_nul_characters)
  static const std::vector<CAddress> fixture_addresses({
  CAddress(
  - CService(CNetAddr(in6addr_loopback), 0 /* port */),
  + CService(CNetAddr(in6_addr(IN6ADDR_LOOPBACK_INIT)), 0 /* port */),
  NODE_NONE,
  0x4966bc61U /* Fri Jan 9 02:54:25 UTC 2009 */
  ),
  CAddress(
  - CService(CNetAddr(in6addr_loopback), 0x00f1 /* port */),
  + CService(CNetAddr(in6_addr(IN6ADDR_LOOPBACK_INIT)), 0x00f1 /* port */),
  NODE_NETWORK,
  0x83766279U /* Tue Nov 22 11:22:33 UTC 2039 */
  ),
  CAddress(
  - CService(CNetAddr(in6addr_loopback), 0xf1f2 /* port */),
  + CService(CNetAddr(in6_addr(IN6ADDR_LOOPBACK_INIT)), 0xf1f2 /* port */),
  static_cast<ServiceFlags>(NODE_WITNESS | NODE_COMPACT_FILTERS | NODE_NETWORK_LIMITED),
  0xffffffffU /* Sun Feb 7 06:28:15 UTC 2106 */
  )
  