osd: do not send peering messages during init

Do not send any peering messages while we are still working our way
through init().

Fixes: #7093
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 35da8f9d80e0c6c33fb6c6e00f0bf38f1eb87d0e)
Signed-off-by: Greg Farnum <greg@inktank.com>