- fix using UNIT_Z when no reset vector is specified for BetterCharacterControl

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10364 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/bullet-common/com/jme3/bullet/control/BetterCharacterControl.java

@@ -384,6 +384,9 @@ public class BetterCharacterControl extends AbstractPhysicsControl implements Ph
      * gravity vector!
      */
     public void resetForward(Vector3f vec) {
+        if (vec == null) {
+            vec = Vector3f.UNIT_Z;
+        }
         localForward.set(vec);
         updateLocalCoordinateSystem();
     }