fix(S3): Adjust usage of guzzle promise

`Promise\promise_for` was deprecated and is now removed and replaced with the static API (`Create::promiseFor`).

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

lib/private/Files/ObjectStore/S3ConnectionTrait.php

@@ -11,7 +11,7 @@ use Aws\Credentials\Credentials;
 use Aws\Exception\CredentialsException;
 use Aws\S3\Exception\S3Exception;
 use Aws\S3\S3Client;
-use GuzzleHttp\Promise;
+use GuzzleHttp\Promise\Create;
 use GuzzleHttp\Promise\RejectedPromise;
 use OCP\ICertificateManager;
 use Psr\Log\LoggerInterface;
@@ -178,7 +178,7 @@ trait S3ConnectionTrait {
 			$secret = empty($this->params['secret']) ? null : $this->params['secret'];
 
 			if ($key && $secret) {
-				return Promise\promise_for(
+				return Create::promiseFor(
 					new Credentials($key, $secret)
 				);
 			}

lib/private/Files/ObjectStore/S3Signature.php

@@ -93,7 +93,7 @@ class S3Signature implements SignatureInterface {
 			}
 		}
 
-		$queryString = http_build_query($query, null, '&', PHP_QUERY_RFC3986);
+		$queryString = http_build_query($query, '', '&', PHP_QUERY_RFC3986);
 
 		return $request->withUri($request->getUri()->withQuery($queryString));
 	}