text: --
  -- After the upgrade to new Spring security the class signature of the serialized tokens as changed
  --
  -- java.io.InvalidClassException: org.springframework.security.core.authority.SimpleGrantedAuthority;
  -- local class incompatible: stream classdesc serialVersionUID = 320, local class serialVersionUID = 400
  --
  -- Therefore we delete all existing tokens. Clients will need to re-authenticate / fetch new tokens
  --
  DELETE from oauth_access_token;
  DELETE from oauth_refresh_token;
  