Fix Guzzle function calls

Since 1.7.0 and 2.0 these functions are turned into static methods.
See https://github.com/guzzle/psr7#upgrading-from-function-api

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

lib/private/Files/ObjectStore/S3Signature.php

@@ -137,7 +137,7 @@ class S3Signature implements SignatureInterface {
 			$modify['set_headers']['X-Amz-Security-Token'] = $token;
 		}
 
-		return Psr7\modify_request($request, $modify);
+		return Psr7\Utils::modifyRequest($request, $modify);
 	}
 
 	private function signString($string, CredentialsInterface $credentials) {
@@ -201,7 +201,7 @@ class S3Signature implements SignatureInterface {
 		$query = $request->getUri()->getQuery();
 
 		if ($query) {
-			$params = Psr7\parse_query($query);
+			$params = Psr7\Query::parse($query);
 			$first = true;
 			foreach ($this->signableQueryString as $key) {
 				if (array_key_exists($key, $params)) {

lib/private/Files/ObjectStore/Swift.php

@@ -27,7 +27,7 @@ namespace OC\Files\ObjectStore;
 
 use GuzzleHttp\Client;
 use GuzzleHttp\Exception\BadResponseException;
-use function GuzzleHttp\Psr7\stream_for;
+use GuzzleHttp\Psr7\Utils;
 use Icewind\Streams\RetryWrapper;
 use OCP\Files\NotFoundException;
 use OCP\Files\ObjectStore\IObjectStore;
@@ -81,13 +81,13 @@ class Swift implements IObjectStore {
 		if (filesize($tmpFile) < SWIFT_SEGMENT_SIZE) {
 			$this->getContainer()->createObject([
 				'name' => $urn,
-				'stream' => stream_for($handle),
+				'stream' => Utils::streamFor($handle),
 				'contentType' => $mimetype,
 			]);
 		} else {
 			$this->getContainer()->createLargeObject([
 				'name' => $urn,
-				'stream' => stream_for($handle),
+				'stream' => Utils::streamFor($handle),
 				'segmentSize' => SWIFT_SEGMENT_SIZE,
 				'contentType' => $mimetype,
 			]);

tests/lib/Http/Client/ResponseTest.php

@@ -9,7 +9,7 @@
 namespace Test\Http\Client;
 
 use GuzzleHttp\Psr7\Response as GuzzleResponse;
-use function GuzzleHttp\Psr7\stream_for;
+use GuzzleHttp\Psr7\Utils;
 use OC\Http\Client\Response;
 
 /**
@@ -25,7 +25,7 @@ class ResponseTest extends \Test\TestCase {
 	}
 
 	public function testGetBody() {
-		$response = new Response($this->guzzleResponse->withBody(stream_for('MyResponse')));
+		$response = new Response($this->guzzleResponse->withBody(Utils::streamFor('MyResponse')));
 		$this->assertSame('MyResponse', $response->getBody());
 	}