Monteverdi: fix band numbering in color setup widget

Band numbers start at 1. The convention is established by QGIS, GDAL, Sentinel-2, MODIS, LANDSAT, etc. Monteverdi displays the band name if it exists from the metadata, otherwise an index that starts at 1.

Fix this confusing widget in Monteverdi:

Modules/Visualization/MonteverdiCore/src/mvdAbstractImageModel.cxx

@@ -171,7 +171,7 @@ AbstractImageModel
          count++)
       {
       std::ostringstream oss;
-      oss <<ToStdString( tr("BAND ") )<< count;
+      oss <<ToStdString( tr("BAND ") )<< count + 1;
       outputBandNames.push_back(oss.str());
       }