Make Registrar.loadByClientId explicitly use memcache

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=154712979

java/google/registry/model/registrar/Registrar.java

@@ -863,7 +863,7 @@ public class Registrar extends ImmutableObject implements Buildable, Jsonifiable
     return ofy().doTransactionless(new Work<Registrar>() {
       @Override
       public Registrar run() {
-        return ofy().load()
+        return ofy().loadWithMemcache()
             .type(Registrar.class)
             .parent(getCrossTldKey())
             .id(clientId)