Fixed 403 link in docs/ref/contrib/gis/install/spatialite.txt.
@@ -86,7 +86,7 @@ Get the latest SpatiaLite library source bundle from the
$ ./configure --target=macosx
-__ https://www.gaia-gis.it/gaia-sins/libspatialite-sources/
+__ http://www.gaia-gis.it/gaia-sins/libspatialite-sources/
.. _spatialite_macos:
