Use config.s3_datastore? to test for s3_data_store (#3435)
Use config.s3_datastore? to test for s3_data_store (#3435)

I found that `s3_datastore` only works if it is set explicitly, but `s3_datastore?` is true whenever the access_key and access_secret are both set. I think this is a better approach, and the existence of `s3_datastore(no question mark)` probably an oversight of mine.
refinery/refinerycms,anitagraham/refinerycms,refinery/refinerycms,anitagraham/refinerycms,anitagraham/refinerycms,refinery/refinerycms