reset cluster error on successful update or sync (#29)

pkg/controller/postgresql.go

@@ -132,6 +132,7 @@ func (c *Controller) processEvent(obj interface{}) error {
 
 			return nil
 		}
+		cl.Error = nil
 		logger.Infof("Cluster '%s' has been updated", clusterName)
 	case spec.EventDelete:
 		logger.Infof("Deletion of the '%s' cluster started", clusterName)
@@ -171,6 +172,7 @@ func (c *Controller) processEvent(obj interface{}) error {
 			logger.Errorf("%v", cl)
 			return nil
 		}
+		cl.Error = nil
 
 		logger.Infof("Cluster '%s' has been synced", clusterName)
 	}