Cleanup after raster import tests using overview

It seems to not be automatic...

git-svn-id: http://svn.osgeo.org/postgis/trunk@12792 b70326c6-7e19-0410-871a-916f4a2858ee
Cross-link UpdateRasterSRID and UpdateGeometrySRID

git-svn-id: http://svn.osgeo.org/postgis/trunk@12793 b70326c6-7e19-0410-871a-916f4a2858ee