test: Fix LogAggregatorSuite.TestReplication in singleton mode
test: Fix LogAggregatorSuite.TestReplication in singleton mode

Only scale to one instance if we’re at two.

Signed-off-by: Jonathan Rudenberg <3692bfa45759a67d83aedf0045f6cb635a966abf@titanous.com>
philiplb/flynn,flynn/flynn,flynn/flynn,lmars/flynn,lmars/flynn,lmars/flynn,philiplb/flynn,lmars/flynn,lmars/flynn,philiplb/flynn,flynn/flynn,benbjohnson/flynn,benbjohnson/flynn,benbjohnson/flynn,philiplb/flynn,benbjohnson/flynn,benbjohnson/flynn,flynn/flynn,flynn/flynn,benbjohnson/flynn,philiplb/flynn