Update physics.adoc
Update physics.adoc

Moved model.addControl(new RigidBodyControl(0)); statement to new line.
jMonkeyEngine/wiki.jmonkeyengine.org,jMonkeyEngine/wiki.jmonkeyengine.org,jMonkeyEngine/wiki.jmonkeyengine.org,jMonkeyEngine/wiki.jmonkeyengine.org