Upgrade commons-validator to 1.6

Version 1.6 upgrades the TLD list to version 2017020400 [1].

The version available at the IANA site [2] at the time of writing
this commit is 2017032102. Prior versions are not provided. Update
the test data to this later version, commenting out the only TLD
that is not supported in 2017020400 ("AFRICA").

[1] fe29c2dd86
[2] http://data.iana.org/TLD/tlds-alpha-by-domain.txt

Change-Id: I2fb3fbc6e4db205d0a1aafdbc6b73a91b2e844ed

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/accounts/AccountIT.java

@@ -417,7 +417,7 @@ public class AccountIT extends AbstractDaemonTest {
             "@example.com",
 
             // Non-supported TLD  (see tlds-alpha-by-domain.txt)
-            "new.email@example.blog");
+            "new.email@example.africa");
     for (String email : emails) {
       EmailInput input = new EmailInput();
       input.email = email;