Add missing import for the exception

apps/encryption/lib/crypto/encryption.php

@@ -25,6 +25,7 @@
 namespace OCA\Encryption\Crypto;
 
 
+use OC\Encryption\Exceptions\DecryptionFailedException;
 use OCA\Encryption\Exceptions\PublicKeyMissingException;
 use OCA\Encryption\Util;
 use OCP\Encryption\IEncryptionModule;
@@ -274,6 +275,7 @@ class Encryption implements IEncryptionModule {
 	 *
 	 * @param string $data you want to decrypt
 	 * @return mixed decrypted data
+	 * @throws DecryptionFailedException
 	 */
 	public function decrypt($data) {
 		if (empty($this->fileKey)) {

apps/encryption/tests/lib/crypto/encryptionTest.php

@@ -231,6 +231,7 @@ class EncryptionTest extends TestCase {
 		);
 	}
 
+	/**
 	 * by default the encryption module should encrypt regular files, files in
 	 * files_versions and files in files_trashbin
 	 *