[raster] raster2pgsql needs a flag to skip band is NODATA check

[dustymugs]

I'm loading GRIB files as out-db rasters with 2.1.0 and hit a sub-optimal situation where the raster load takes forever.

​ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/DF.gr2/DC.ndfd/AR.conus/VP.001-003/ds.wdir.bin

I need to double-check but from what I can tell, the problem has to do with rt_band_check_is_nodata(band).

The fix should be applied for both 2.0 and 2.1 as the loader hasn't changed much between versions.

[dustymugs]

Since the raster is being loaded as out-db, a convenient work-around is to load the whole file as one raster and then use ST_Tile().

[dustymugs]

Fixed in trunk at r12092. Fixed in -2.1 in r12093. Doesn't need fixing in -2.0 as that version didn't have the check in place.