Fix some tests

apps/dav/tests/unit/Connector/Sabre/FilesPluginTest.php

@@ -471,7 +471,7 @@ class FilesPluginTest extends TestCase {
 		$node = $this->getMockBuilder('\OCA\DAV\Connector\Sabre\Node')
 			->disableOriginalConstructor()
 			->getMock();
-		$node->expects($this->once())
+		$node->expects($this->at(0))
 			->method('getFileInfo')
 			->willReturn($fileInfoFolderATestTXT);
 
@@ -545,7 +545,7 @@ class FilesPluginTest extends TestCase {
 				->getMock();
 
 		$request
-			->expects($this->once())
+			->expects($this->at(1))
 			->method('getPath')
 			->will($this->returnValue('test/somefile.xml'));
 

apps/dav/tests/unit/DAV/SystemPrincipalBackendTest.php

@@ -45,7 +45,12 @@ class SystemPrincipalBackendTest extends TestCase {
 			[[[
 				'uri' => 'principals/system/system',
 				'{DAV:}displayname' => 'system',
-			]], 'principals/system'],
+			],
+			[
+				'uri' => 'principals/system/public',
+				'{DAV:}displayname' => 'public',
+			]
+			], 'principals/system'],
 		];
 	}