fixed char forward since it's a rotated capsule

Project/Assets/ML-Agents/Examples/Worm/Scripts/WormAgent.cs

     /// </summary>
     void RewardFunctionFacingTarget()
     {
-        m_FacingDot = Vector3.Dot(m_DirToTarget.normalized, bodySegment0.forward);
+//        m_FacingDot = Vector3.Dot(m_DirToTarget.normalized, bodySegment0.forward);
+        m_FacingDot = Vector3.Dot(m_DirToTarget.normalized, bodySegment0.up);
         AddReward(0.01f * m_FacingDot);
     }