fix: currentToken is removed from localstorage on refresh

[joymyr]

Description

On web, using version 0.5.2, the FlutterSecureStorage.oidc.secureTokens.currentToken is removed shortly after refresh. Could it be related to the feature for refreshing tokens on init? I don't have this issue with 0.5.1.

Steps To Reproduce

1. Log in on web
2. Verify that currentToken is added to local storage
3. Refresh
4. currentToken is now gone

Expected Behavior

CurrentToken should still be there after refresh

[ahmednfwela]

hi @joymyr , I can't reproduce this, is it similar to #69 ?
if not, then please provide a reproducible example