[storm] initialize_globals() is not thread safe

[Ivan Zakrevskyi]

Hi, all.

I've an error on highload uwsgi.

Maybe initialize_globals() should lock threads.

There is single Store object for each thread, according docs:
https://storm.canonical.com/Manual#Working_with_multiple_threads

  File "./community/views/components/sharing.py", line 33, in process
    twitter_profile = store.get(StTwitterProfile, (context_id, site.owner_id))

  File "./.virtualenvs/rebelmouse/local/lib/python2.7/site-packages/storm/store.py",
line 181, in get
    variable = column.variable_factory(value=variable)

RuntimeError: initialize_globals() failed the first time it was run