Disable NdbGetInAddr test in CI

It needs ipv6, and it appears to need public-internet DNS resolution,
which is a tacky thing to do in a unit test.

Author: piki

storage/ndb/src/common/portlib/NdbTCP.cpp

@@ -498,6 +498,11 @@ can_resolve_hostname(const char* name)
 
 TAPTEST(NdbGetInAddr)
 {
+  if (getenv("DISABLE_IPV6_TESTS")) {
+    // fails when ipv6 is present but disabled
+    GTEST_SKIP();
+  }
+
   socket_library_init();
 
   if (can_resolve_hostname("localhost"))