Cache is unreadable by non-original user

[djw8605]

With xrootd-multiuser, scitokens changes user before reading the keycache. The keycache is in a directory with 700 permissions, and therefore is unable to read the keycache on initial creation.

The directory should be created with 755, there is nothing private in the keycache. But should the cache itself be writable by other users? It would need to be in order to update an expired public key.