Minor if-else simplification

Graph.cpp

                         // ...jezeli niespelnione - pomijamy ruch
                         continue;
 
-                    if(nextRouteLength == -1)
-                    {
-                        nextRouteLength = neighbourRouteLength;
-                        nextRoute = neighbourRoute;
-                        nextTabu.at(1) = i;
-                        nextTabu.at(2) = j;
-                    }
-                    else if(nextRouteLength > neighbourRouteLength)
+                    if(nextRouteLength == -1 || nextRouteLength > neighbourRouteLength)
                     {
                         nextRouteLength = neighbourRouteLength;
                         nextRoute = neighbourRoute;