fix: double if constructor

src/main/java/it/finanze/sanita/fse2/ms/gtw/dispatcher/config/kafka/oauth2/CustomAuthenticateCallbackHandler.java

@@ -1,17 +1,6 @@
 //Copyright (c) Microsoft Corporation. All rights reserved.
 //Licensed under the MIT License.
 
-/*
- * SPDX-License-Identifier: AGPL-3.0-or-later
- *
- * Copyright (C) 2023 Ministero della Salute
- *
- * This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.
- */
 package it.finanze.sanita.fse2.ms.gtw.dispatcher.config.kafka.oauth2;
 
 import java.io.ByteArrayInputStream;
@@ -101,7 +90,6 @@ public void handle(Callback[] callbacks) throws IOException, UnsupportedCallback
     private OAuthBearerToken getOAuthBearerToken() throws MalformedURLException, InterruptedException, ExecutionException, TimeoutException {
         if (this.aadClient == null) {
             synchronized(this) {
-                if (this.aadClient == null) {
                 	IClientCredential credential = null;
             	    try (FileInputStream certificato = new FileInputStream(new File(pfxPathName))) {
                 		credential = ClientCredentialFactory.createFromCertificate(certificato, this.pwd);	
@@ -112,7 +100,6 @@ private OAuthBearerToken getOAuthBearerToken() throws MalformedURLException, Int
                     this.aadClient = ConfidentialClientApplication.builder(this.appId, credential)
                             .authority(this.tenantId)
                             .build();
-                }
             }
         }