Fixed a bug in levmar for when it failed to solve for the update

nonlin.cpp

@@ -380,6 +380,7 @@ NonlinOut levmar(const NonlinParam& p, const NonlinCF& cfo)
       p.SetCF(ncf);                                           // Store value of cost-function
     }
     else {                                                    // If last step was unsuccesful
+      success = false;
       olambda = p.Lambda();                                   // Returning to same H, so must undo old lambda
       p.SetLambda(10.0*p.Lambda());                           // Increase nudge factor
       p.SetCF(p.CF());                                        // Push another copy of best cost function value thus far