user_token refresh issue

[elestedt]

Describe the bug
When only user_token is used getVersion fails onread after access token has expired, doesn't seem to use the refresh_token in this case

** Versions **

• Plugin: 1.8.0
• Vault: Enterprise 1.17.3
• Artifactory 7.90.8 which requires user authentication on everything except ping

To Reproduce
Steps to reproduce the behavior:

1. Clean plugin install
2. vault write artifactory/config/admin only, no token, other settings might be ok
3. Write in user token

USERNAME=$(whoami)
TOKEN=
REFRESH=
vault write artifactory/config/user_token/${USERNAME} access_token=${TOKEN} refresh_token=${REFRESH}

5. Read token to verify

vault read artifactory/user_token/${USERNAME}

6. Wait longer than token expiry, but shorter than refresh token expiry
7. `vault read now fails and logs shows only when debug logs are activated

 [ERROR] secrets.artifactory.artifactory_fd15a342.artifactory.artifactory-secrets-plugin_1.8.0: Unable to get Artifactory Version. Check url and access_token fields. TLS connection verification with Artifactory can be skipped by setting bypass_artifactory_tls_verification field to ‘true’: err=\“could not get the system version: HTTP response 401\” func=checkVersion ver=\“\"

Expected behavior
Token refreshed and a new token issued

[alexhung]

@elestedt Thanks for the report! I've added this to our plan to investigate.