compile error with latest g2o

[samsdolphin]

The first three lines of code should be updated to:

auto linearSolver = g2o::make_unique<LinearSolverCSparseBlockSolverX::PoseMatrixType>();
auto blockSolver = g2o::make_unique(std::move(linearSolver));
OptimizationAlgorithmLevenberg* optimizationAlgorithm = new OptimizationAlgorithmLevenberg(std::move(blockSolver));