fix "headercheck":

part of https://github.com/assimp/assimp/issues/534

code/MD4FileData.h

@@ -46,9 +46,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <vector>
 #include <sstream>
 
-#include "../include/aiTypes.h"
-#include "../include/aiMesh.h"
-#include "../include/aiAnim.h"
+#include "../include/assimp/types.h"
+#include "../include/assimp/mesh.h"
+#include "../include/assimp/anim.h"
 
 #if defined(_MSC_VER) ||  defined(__BORLANDC__) ||	defined (__BCPLUSPLUS__)
 #	pragma pack(push,1)
@@ -215,4 +215,4 @@ struct Frame
 };
 };
 
-#endif // !! AI_MD4FILEHELPER_H_INC
+#endif // !! AI_MD4FILEHELPER_H_INC