Adapt to new PermissionBackend interface

Change-Id: I4c1eeba68c447790f0bd24a495b8bfe66e9364a2
diff --git a/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java b/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
index 63051cd..a595a48 100644
--- a/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
+++ b/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
@@ -250,7 +250,7 @@
   public Response<?> apply(BranchResource resource, BranchInput input)
       throws IOException, ConfigInvalidException, GitAPIException, AuthException,
           PermissionBackendException {
-    permissionBackend.user(identifiedUser).check(GlobalPermission.ADMINISTRATE_SERVER);
+    permissionBackend.currentUser().check(GlobalPermission.ADMINISTRATE_SERVER);
     info(
         "manual trigger for %s:%s by %d. Config: %s",
         resource.getBranchKey().getParentKey().get(),