manager: update crs scheduling mode once per round

manager: update crs scheduling mode once per round

Pretty safe to do as we recompute everything per round anyway (and
much more often on top of that, but that's another topic).

Actually I'd argue that it's safer as this way a user doesn't need to
actively restart the manager, which grinds much more gears and
watchdog changes than checking periodically and updating it
internally. Plus, a lot of admins won't expect that they need to
restart the current active master and thus they'll complain that
their recently made change to the CRS config had no effect/the CRS
doesn't work at all.

We should codify such a change in test for this though.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>