And also when using eureka-first for discovering config server.
The EurekaClient is very rigid and initializes itself, registering
with the remote service on instantiation. Hance it needs to be
in @RefreshScope for it to be properly refreshable. Doing that
leads to a sequence of other changes (e.g. to account for the
fact that there is no @RefreshScope in bootstrap context).

Fixes gh-551