Skip RabbitMQ cluster test in standalone

PROD-36045 implements a new RabbitMQ option: standalone mode, that
enables to use RabbitMQ in non-clustered configurations. Existing
CVP test has to be fixed to avoid failures when RabbitMQ in the
standalone mode.

Closes-Bug: PROD-36077
Change-Id: I8cf66bd8a6e1d99052e82d8662dbf563493eec4a
diff --git a/test_set/cvp-sanity/tests/test_rabbit_cluster.py b/test_set/cvp-sanity/tests/test_rabbit_cluster.py
index da5ca3f..cd18baf 100644
--- a/test_set/cvp-sanity/tests/test_rabbit_cluster.py
+++ b/test_set/cvp-sanity/tests/test_rabbit_cluster.py
@@ -17,6 +17,9 @@
         fun='pillar.get',
         param='rabbitmq:cluster',
         expr_form='pillar')
+    # skip the test if there is no cluster data in pillars
+    if sum([len(v) for v in rabbitmq_pillar_data.values()]) == 0:
+        pytest.skip("No RabbitMQ cluster pillar available")
     # creating dictionary {node:cluster_size_for_the_node}
     # with required cluster size for each node
     control_dict = {}