luci-base: don't fail getInitList if no indexes can be determined

Gracefully handle missing indexes in the luci rpcd plugin getInitList
procedure.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

modules/luci-base/root/usr/share/rpcd/ucode/luci

@@ -26,8 +26,8 @@ const methods = {
 				let idx = init_index(name);
 
 				scripts[name] = {
-					index: idx[0],
-					stop: idx[1],
+					index: idx?.[0],
+					stop: idx?.[1],
 					enabled: init_enabled(name)
 				};
 			}