Improve retry logic for Stale Element Exceptions

Better exception retry logic

Change methods to lambdas

cms/djangoapps/contentstore/features/static-pages.py

@@ -67,7 +67,7 @@ def get_index(name):
     page_name_css = 'section[data-type="HTMLModule"]'
     all_pages = world.css_find(page_name_css)
     for i in range(len(all_pages)):
-        if all_pages[i].html == '\n    {name}\n'.format(name=name):
+        if world.retry_on_exception(lambda: all_pages[i].html) == '\n    {name}\n'.format(name=name):
             return i
     return None