Fix wrong warning in cluster-list if no clusters and no VIMs

Change-Id: I91110bed74adc17f46d5ba425cf88661bce8a66e
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osmclient/sol005/cluster.py b/osmclient/sol005/cluster.py
index b1291c2..801f766 100644
--- a/osmclient/sol005/cluster.py
+++ b/osmclient/sol005/cluster.py
@@ -140,7 +140,7 @@
         cluster_list = self.list(filter)
         vim_list = self._client.vim.list()
         self._logger.debug(f"VIM list: {vim_list}")
-        if not vim_list:
+        if cluster_list and not vim_list:
             self._logger.warning(
                 "Could not complete cluster info with VIM account info"
             )