Stop removing postgresql-8.3-603.jdbc4.jar and postgis-stubs-1.3.3.jar

https://github.com/GeoNode/geoserver-geonode-ext/commit/78286e22e4d96df1cc9400cab5d655f556853e30 is required until this is fixed https://osgeo-org.atlassian.net/browse/GEOS-11882