dont draw shadows with 0 blur_radius

src/c3nav/mapdata/utils/svg.py

@@ -204,7 +204,7 @@ class SVGImage:
 
             if altitude is not None or elevation is not None:
                 blur_radius = float(1 if elevation is None else elevation)
-
+                if blur_radius:
                     buffered_geometry = translate(geometry.buffer(blur_radius/20),
                                                   xoff=blur_radius/40, yoff=-blur_radius/40)
                     shadow_element = self._create_geometry(buffered_geometry)