Remove obsolete comment.

init() is from pre-flattening days

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=154256803

javatests/google/registry/flows/domain/DomainCreateFlowTest.java

@@ -896,7 +896,6 @@ public class DomainCreateFlowTest extends ResourceFlowTestCase<DomainCreateFlow,
 
   @Test
   public void testFailure_alreadyExists_triggersFailfast() throws Exception {
-    // This fails fast and throws DomainAlreadyExistsException from init() as a special case.
     persistContactsAndHosts();
     persistActiveDomain(getUniqueIdFromCommand());
     try {