servo: Merge #17286 - Set stylesheet url_data correctly for import rule (from upsuper:import-url-data); r=heycam

This is the servo side change of [bug 1331291](https://bugzilla.mozilla.org/show_bug.cgi?id=1331291).

Source-Repo: https://github.com/servo/servo
Source-Revision: abd5f3ed59ba95d4532b9a86f435c781fd75695f

servo/components/script/stylesheet_loader.rs

@@ -160,7 +160,7 @@ impl FetchResponseListener for StylesheetContext {
                                                   &data,
                                                   protocol_encoding_label,
                                                   Some(environment_encoding),
-                                                  &final_url,
+                                                  final_url,
                                                   Some(&loader),
                                                   win.css_error_reporter());
                 }