Fix the docs - smallrye.jwt.resolve-remote-keys-at-startup and cache

[zilinjak]

Hey,
lately I have been using smallrye jwt a lot. I have found bug where the cache of JWKS wasn't being refreshed.
This ended up due to the implementation of smallrye.jwt.resolve-remote-keys-at-startup can you please fix the docs and add note that the smallrye.jwt.resolve-remote-keys-at-startup will mean that the keys will be fetched at start and cache WON'T be used.

[sberyozkin]

@zilinjak Hi, it is not a doc bug then but the runtime bug, as in this this case the keys must be refreshable