Fix error with empty catch block

Change-Id: I0195ff222f858acf17d829c322feb8914dcec7d3
Related-Prod: PROD-28494 (PROD:28494)
diff --git a/validate-cloud.groovy b/validate-cloud.groovy
index 5dd8008..c73325c 100644
--- a/validate-cloud.groovy
+++ b/validate-cloud.groovy
@@ -76,6 +76,7 @@
                              report_dir = REPORT_DIR
                          }
                     } catch (MissingPropertyException e) {
+                         common.warningMsg(e)
                     }
                     def rally_variables = ["floating_network=${FLOATING_NETWORK}",
                                            "rally_image=${RALLY_IMAGE}",