Merge pull request #3993 from jjimenezshaw/lost-resouce-links

[doc]: remove unneeded or broken links in resource_files.rst

docs/source/resource_files.rst

@@ -254,16 +254,6 @@ Portugal
 
 `Portuguese grids <http://www.fc.up.pt/pessoas/jagoncal/coordenadas/index.htm>`__ for ED50, Lisbon 1890, Lisbon 1937 and Datum 73
 
-South Africa
-................................................................................
-
-`South African grid <http://eepublishers.co.za/article/datum-transformations-using-the-ntv2-grid.html>`__ (Cape to Hartebeesthoek94 or WGS84)
-
-Spain
-................................................................................
-
-`Spanish grids <http://www.ign.es/ign/layoutIn/herramientas.do#DATUM>`__ for ED50.
-
 
 HTDP
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++