DOC / Tutorial "Draping a dataset on top of a topographic surface": Update link to EU flag image (#4619)

Add general link to EU flage image

Author: yvonnefroehlich

examples/tutorials/advanced/draping_on_3d_surface.py

@@ -97,7 +97,7 @@
 
 # Load a PNG image of the EU flag using rasterio into an xarray.DataArray.
 # The original image is available on Wikimedia Commons at
-# https://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Flag_of_Europe.svg/1024px-Flag_of_Europe.svg.png
+# https://commons.wikimedia.org/wiki/File:Flag_of_Europe.svg
 # but we use a cached version on the GMT data server.
 url_to_image = "https://oceania.generic-mapping-tools.org/cache/euflag.png"
 with rasterio.open(url_to_image) as dataset: