HingeJoint.enableMotor() not working

[stephengold]

TestAttachGhostObject and TestPhysicsHingeJoint both use the enableMotor() method to drive the motion of a HingeJoint. Even with the maxMotorImpulse cranked up to 1e10, invoking enableMotor() appears to have no effect in these simulations. I tested both JBullet and NativeBullet.

[pspeed42]

This "fix" makes no sense at all but is otherwise completely harmless for a 3.2.2 release.

[stephengold]

A new issue that's possibly related: #1141