Fix typo in HashedAbstractEnvironment comment
Fix typo in HashedAbstractEnvironment comment

Summary:
typo

Created from Diffusion's 'Open in Editor' feature.

Reviewed By: arnaudvenet

Differential Revision: D7672510

fbshipit-source-id: 00fe27f2f0970c843bb7dc2ec18edcc01446ee95

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex