[#2952] Add the missing close client call in SetUniverseKey

Summary:
Add a missing closeClient call inside of SetUniverseKey , this would keep the client
connection around and eventually causing OOM.

Test Plan: TBD

Reviewers: bogdan, rao, daniel

Reviewed By: rao, daniel

Subscribers: jenkins-bot, yugaware, rao

Differential Revision: https://phabricator.dev.yugabyte.com/D7583

managed/src/main/java/com/yugabyte/yw/commissioner/SetUniverseKey.java

@@ -82,6 +82,8 @@ private void setKeyInMaster(Universe u, HostAndPort masterAddr, byte[] keyRef, b
                     masterAddr.toString()
             );
             LOG.error(errMsg, e);
+        } finally {
+            ybService.closeClient(client, hostPorts);
         }
     }