Fix string format of the JS test assertion failure following 7c2e9027c2 (cxxtest expects a char* instead of a std::wstring, so newlines were printed as \n characters).

Differential Revision: https://code.wildfiregames.com/D952
Fixes #4807

This was SVN commit r20292.

source/test_setup.cpp

@@ -131,7 +131,7 @@ namespace
 {
 	void script_TS_FAIL(ScriptInterface::CxPrivate* UNUSED(pCxPrivate), const std::wstring& msg)
 	{
-		TS_FAIL(msg);
+		TS_FAIL(utf8_from_wstring(msg).c_str());
 	}
 }