Fixed _CRT_SECURE_NO_WARNINGS macro redefinition warning
diff --git a/xmltest.cpp b/xmltest.cpp
index 6fdc162..55b597d 100644
--- a/xmltest.cpp
+++ b/xmltest.cpp
@@ -1,5 +1,7 @@
 #if defined( _MSC_VER )

-	#define _CRT_SECURE_NO_WARNINGS		// This test file is not intended to be secure.

+	#if !defined( _CRT_SECURE_NO_WARNINGS )

+		#define _CRT_SECURE_NO_WARNINGS		// This test file is not intended to be secure.

+	#endif

 #endif

 

 #include "tinyxml2.h"