mon: osd-pool-create test EAGAIN when pending

Test that if the ruleset is found in the pending paxos proposal, the
pool creation will try again.

Signed-off-by: Loic Dachary <loic@dachary.org>
mon: osd-pool-create test no longer use hardcoded ruleset

For erasure-code the ruleset must be specified instead of relying on an
hardcoded value. Adapt the test to this for tests that do not otherwise
change behavior.

Signed-off-by: Loic Dachary <loic@dachary.org>