Fixed a error in the unit tests, that occurred when running under OS X

Author: Taritsyn

test/JavaScriptEngineSwitcher.Tests/ChakraCore/CommonTests.cs

@@ -234,7 +234,7 @@ public void MappingEngineLoadErrorDuringOutOfMemoryIsCorrect()
 				jsEngine = new ChakraCoreJsEngine(
 					new ChakraCoreSettings
 					{
-						MemoryLimit = new UIntPtr(640 * 1024),
+						MemoryLimit = new UIntPtr(8 * 1024),
 						DisableFatalOnOOM = true
 					}
 				);