Update bazlets to latest stable-2.15 and adjust to 2.15.4 API

Change-Id: I8d3551eb982907e1fbad0ffaf65061d2677275ea

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 1cba3d1..3517e8b 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "7ce9a3f58f030635b3a1229b7fb4c62ee7979bc8",
+    commit = "88570121c377a8a94c76915566114bf02113a7d9",
     # local_path = "/home/<user>/projects/bazlets",
 )
 

src/main/java/com/googlesource/gerrit/plugins/importer/AccountUtil.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/importer/AccountUtil.java b/src/main/java/com/googlesource/gerrit/plugins/importer/AccountUtil.java
index b3f62de..feb5da6 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/importer/AccountUtil.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/importer/AccountUtil.java
@@ -33,6 +33,7 @@
 import com.google.gerrit.server.account.AuthRequest;
 import com.google.gerrit.server.account.CreateAccount;
 import com.google.gerrit.server.account.VersionedAuthorizedKeys;
+import com.google.gerrit.server.account.externalids.ExternalId;
 import com.google.gerrit.server.config.AuthConfig;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -113,7 +114,7 @@
   private Account.Id createAccountByLdapAndAddSshKeys(GerritApi api, AccountInfo acc)
       throws NoSuchAccountException, IOException, OrmException, RestApiException,
           ConfigInvalidException {
-    if (!acc.username.matches(Account.USER_NAME_PATTERN)) {
+    if (!ExternalId.isValidUsername(acc.username)) {
       throw new NoSuchAccountException(String.format("User %s not found", acc.username));
     }