print exception when using default

Author: madhephaestus

src/main/java/com/neuronrobotics/sdk/addons/kinematics/DHChain.java

@@ -333,7 +333,8 @@ public String toString(){
 	 */
 	public DhInverseSolver getInverseSolver() {
 		if(is==null){
-			is=new DhInverseSolver() {
+			Log.error(new RuntimeException("No Solver defined!"));
+			return new DhInverseSolver() {
 
 				@Override
 				public double[] inverseKinematics(TransformNR target,