fix: handle sftp private key as password

Signed-off-by: Robin Appelman <robin@icewind.nl>

Author: icewind1991

apps/files_external/lib/Lib/Auth/PublicKey/RSAPrivateKey.php

@@ -31,7 +31,8 @@ public function __construct(
 				(new DefinitionParameter('password', $l->t('Password')))
 					->setFlag(DefinitionParameter::FLAG_OPTIONAL)
 					->setType(DefinitionParameter::VALUE_PASSWORD),
-				new DefinitionParameter('private_key', $l->t('Private key')),
+				(new DefinitionParameter('private_key', $l->t('Private key')))
+					->setType(DefinitionParameter::VALUE_PASSWORD),
 			]);
 	}