fix: index key for identifier

Author: kenjis

src/Database/Migrations/2020-12-28-223112_create_auth_tables.php

@@ -64,7 +64,7 @@ public function up(): void
             'success'    => ['type' => 'tinyint', 'constraint' => 1],
         ]);
         $this->forge->addPrimaryKey('id');
-        $this->forge->addKey('identifier');
+        $this->forge->addKey(['id_type', 'identifier']);
         $this->forge->addKey('user_id');
         // NOTE: Do NOT delete the user_id or identifier when the user is deleted for security audits
         $this->forge->createTable('auth_logins', true);
@@ -84,7 +84,7 @@ public function up(): void
             'success'    => ['type' => 'tinyint', 'constraint' => 1],
         ]);
         $this->forge->addPrimaryKey('id');
-        $this->forge->addKey('identifier');
+        $this->forge->addKey(['id_type', 'identifier']);
         $this->forge->addKey('user_id');
         // NOTE: Do NOT delete the user_id or identifier when the user is deleted for security audits
         $this->forge->createTable('auth_token_logins', true);