open: Mention full URL in 'Failed to open' error message

Just showing the URL's path is confusing, that would show '/' for
something like foo://bar.

Userland/open.cpp

@@ -59,7 +59,7 @@ int main(int argc, char* argv[])
         }
 
         if (!Desktop::Launcher::open(url)) {
-            warnln("Failed to open '{}'", url.path());
+            warnln("Failed to open '{}'", url);
             all_ok = false;
         }
     }