fix(mako): use new discoveryRestUrl field for json download

src/mako/deps.mako

@@ -184,7 +184,7 @@ help${agsuffix}:
 %>\
 ${fake_target}:
 	@mkdir -p ${target_dir}
-	@wget -nv ${discovery_url + info['discoveryLink']} -O ${target}
+	@wget -nv ${info['discoveryRestUrl']} -O ${target}
 % endfor
 
 update-json: ${' '.join(json_api_targets)}