Revert empty select in agent

Signed-off-by: Pavol Loffay <ploffay@redhat.com>

cmd/agent/main.go

@@ -65,7 +65,7 @@ func main() {
 			if err := agent.Run(); err != nil {
 				return errors.Wrap(err, "Failed to run the agent")
 			}
-			return nil
+			select {}
 		},
 	}