Refactor ConfigMockTrait to mocked ConfigCache

tests/src/Core/Cache/MemcachedCacheDriverTest.php

@@ -6,15 +6,16 @@ namespace Friendica\Test\src\Core\Cache;
 use Friendica\Core\Cache\CacheDriverFactory;
 
 /**
- * @runTestsInSeparateProcesses
- * @preserveGlobalState disabled
  * @requires extension memcached
  */
 class MemcachedCacheDriverTest extends MemoryCacheTest
 {
 	protected function getInstance()
 	{
-		$this->mockConfigGet('system', 'memcached_hosts', [0 => 'localhost, 11211']);
+		$this->configCache
+			->shouldReceive('get')
+			->with('system', 'memcached_hosts', NULL)
+			->andReturn([0 => 'localhost, 11211']);
 
 		$this->cache = CacheDriverFactory::create('memcached');
 		return $this->cache;