Sentinel-1 netCDF raster data is flipped in azimuth

[mortenwh]

OPeNDAP streams and netCDF files are read differently by gdal. The OPeNDAP streams are read by specifying the get parameters to the OPeNDAP url. The get parameters specify the reference dimensions, e.g., x and y. Since these are specified, the raster data is correctly referenced to the GCPs. However, when gdal reads a raster band from netCDF, it reads it "blindly". This is risky, since the definition of origo may be different in gdal vs the original data (e.g., first line starts in upper left corner or in lower left corner). For Sentinel-1, the raster data is flipped in relation to the GCPs, so we need to flip the GCP line vector as well.