Update MikktspaceTangentGenerator.java

forgot to add import for VertexBuffer.Type;

Author: yaRnMcDonuts

jme3-core/src/main/java/com/jme3/util/mikktspace/MikktspaceTangentGenerator.java

@@ -34,6 +34,7 @@
 import com.jme3.math.FastMath;
 import com.jme3.math.Vector3f;
 import com.jme3.scene.*;
+import com.jme3.scene.VertexBuffer.Type;
 import com.jme3.util.*;
 
 import java.util.ArrayList;