Use username from notedb in serviceuser.db

With auth.userNameToLowerCase set, serviceusers were not listed
correctly in the UI, since the capitalization in serviceuser.db
was different to the one in notedb.

Change-Id: I52f51777f3306c293e0a914b8815e69c86220d48
diff --git a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/CreateServiceUser.java b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/CreateServiceUser.java
index 50fc6a0..9a04e0e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/CreateServiceUser.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/CreateServiceUser.java
@@ -179,11 +179,11 @@
     String creationDate = rfc2822DateFormatter.format(new Date());
 
     Config db = storage.get();
-    db.setInt(USER, username, KEY_CREATOR_ID, creatorId.get());
+    db.setInt(USER, response.username, KEY_CREATOR_ID, creatorId.get());
     if (creator != null) {
-      db.setString(USER, username, KEY_CREATED_BY, creator);
+      db.setString(USER, response.username, KEY_CREATED_BY, creator);
     }
-    db.setString(USER, username, KEY_CREATED_AT, creationDate);
+    db.setString(USER, response.username, KEY_CREATED_AT, creationDate);
 
     MetaDataUpdate md = metaDataUpdateFactory.create(allProjects);
     md.setMessage("Create service user '" + username + "'\n");