Added support for cube label files before assuming cubelist. Fixes #5350

    QList<QString> cubesToOpen;

    // If the file is a cub file, we add the path to it to our list of cubes to open.

    if ( cubeFileName.suffix() == "cub" || cubeFileName.suffix() == "cube" ) {

    if ( cubeFileName.suffix() == "cub" || cubeFileName.suffix() == "cube" || cubeFileName.suffix() == "lbl") {

      // cubesToOpen.append(cubeFileName.absoluteFilePath());

      cubesToOpen.append(cubeFileName.filePath());

    }

    else {

      // If the file received isn't a .cub, it has to be a cubelist. We read every cube in the cubelist

      // And append it to the cubesToOpen QList so that we can open them.

      // If the file received isn't a cube or label, it has to be a cubelist. We read every cube in

      // the cubelist and append it to the cubesToOpen QList so that we can open them.

      QFile file(cubename);

      file.open(QIODevice::ReadOnly);