[openpgp] Fix usage of junit annotations in SecretKeyBackupHelperTestc

The unit test used the JUnit 4 annotations @BeforeClass and
@afterclass when it should use the JUnit 5 variants @BeforeAll and
@afterall.

smack-openpgp/src/test/java/org/jivesoftware/smackx/ox/SecretKeyBackupHelperTest.java

@@ -38,9 +38,9 @@
 
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.jxmpp.jid.BareJid;
 import org.jxmpp.jid.impl.JidCreate;
@@ -49,14 +49,11 @@
 
 public class SecretKeyBackupHelperTest extends SmackTestSuite {
 
-    private static final File basePath;
+    private static File basePath;
 
-    static {
-        try {
-            basePath = Files.createTempDirectory("ox_secret_keys_").toFile();
-        } catch (IOException e) {
-            throw new AssertionError(e);
-        }
+    @BeforeAll
+    public static void createTemptDir() throws IOException {
+        basePath = Files.createTempDirectory("ox_secret_keys_").toFile();
     }
 
     @Test
@@ -98,8 +95,7 @@ public void createAndDecryptSecretKeyElementTest()
         Assertions.assertArrayEquals(secretKeys.getEncoded(), secretKeyRing.getEncoded());
     }
 
-    @AfterClass
-    @BeforeClass
+    @AfterAll
     public static void deleteDirs() throws IOException {
         org.apache.commons.io.FileUtils.deleteDirectory(basePath);
     }