fix reachability again

src/DummyConnector.cpp

@@ -40,7 +40,7 @@ bool DummyConnector::reachableObject(const Object &robot, const Object &object)
     }
 
     // if the location is more than 750mm away from the robot base it is too far away
-    if (std::sqrt(dx*dx + dy*dy + dz+dz) > 0.75) {
+    if (std::sqrt(dx*dx + dy*dy + dz*dz) > 0.75) {
         return false;
     }