message: revert blockstack protocol handler
diff: @@ -5,7 +5,7 @@ import { decodeToken } from 'jsontokens'
  import { makeAuthRequest, verifyAuthResponse } from './authMessages'
  import { updateQueryStringParameter } from '../index'
  -const BLOCKSTACK_HANDLER = "web+blockstack"
  +const BLOCKSTACK_HANDLER = "blockstack"
  const BLOCKSTACK_STORAGE_LABEL = "blockstack"
  const DEFAULT_BLOCKSTACK_HOST = "https://blockstack.org/auth"
  