MDL-9925 - When a user presses cancel on restore they are sent to

/admin/. For teachers this gives an ugly access denied message,
so instead send them back to the course they came from.

Thanks to Wen Hao Chuang for the fix!

merged from MOODLE_19_STABLE

backup/restore.php

@@ -109,7 +109,7 @@
     if ($cancel) {
         print_header("$site->shortname: $strcourserestore", $site->fullname, $navigation);
         print_heading(get_string("restorecancelled"));
-        print_continue("$CFG->wwwroot/$CFG->admin/index.php");
+        print_continue("$CFG->wwwroot/course/view.php?id=".$id);
         print_footer();
         exit;
     }