vlkb: cosmetic: (usage text for cutout said overlap)

data-access/engine/src/vlkb/src/main.cpp

@@ -258,7 +258,7 @@ int cmd_cutout(int argc, char * argv[])
    if (argc != 4)
    {
       std::cerr
-         << "Usage:  overlap <filename.fits> <extnum> <region>\n"
+         << "Usage:  cutout <filename.fits> <extnum> <region>\n"
          << "\n"
          << "Calculate overlap between HDU in file and region.\n\nregion in JSON form of VO-SODA params. For example 'POS=CIRCLE 21.4458 -1.373 0.1' :\n"
          " \'{\"pos\":{\"circle\":{\"lat\":-1.373,\"lon\":21.4458,\"radius\":0.1},\"system\":\"ICRS\"},\"service\":\"SUBIMG\"}\'\n";