Revert "Bug 986329 - Fix test_settings_XXX.py with JavascriptException: TypeError: window.wrappedJSObject.Settings is undefined"

This reverts commit fab38c4384733c3eed51ceaec2787c7d5962dcd3.
Bug 986329 - Fix test_settings_XXX.py with JavascriptException: TypeError: window.wrappedJSObject.Settings is undefined
Merge pull request #17596 from bebef1987/fix_set

Bug 986329 - Fix test_settings_XXX.py with JavascriptException: