Compilation fix against really ancient PostgreSQL version

git-svn-id: https://svn.osgeo.org/gdal/trunk@25647 f0d54148-0727-0410-94bb-9a71ac55c965
Compilation fix for ancient GCC

git-svn-id: https://svn.osgeo.org/gdal/trunk@25648 f0d54148-0727-0410-94bb-9a71ac55c965