Update collada-exporter link

(cherry picked from commit 312fdca11d4a7f05cbeb5920082677c2b5c9053a)

tutorials/3d/importing_3d_scenes.rst

@@ -64,7 +64,7 @@ Blender also has built-in collada support, but It's really broken and
 should not be used either.
 
 Godot provides a `Python
-Plugin <https://github.com/godotengine/godot/tree/master/tools/export/blender25>`__
+Plugin <https://github.com/godotengine/collada-exporter>`__
 that will do a much better job at exporting the scenes.
 
 The import process