Fixed #625: Remove error from race condition by rechecking if the dir is there rather than checking if the creation existed, it should be an idempotent action.
Fixed #625: Remove error from race condition by rechecking if the dir is there rather than checking if the creation existed, it should be an idempotent action.

twistor/flysystem,mhlavac/flysystem,twistor/flysystem,mhlavac/flysystem