fix typo classes:

Change-Id: Ia7ceba336c5476b2cb18de3e3b2d57e16bf2477b
diff --git a/classes/cluster/k8s_aio_calico/infra/config.yml b/classes/cluster/k8s_aio_calico/infra/config.yml
index c8f630f..fe16242 100644
--- a/classes/cluster/k8s_aio_calico/infra/config.yml
+++ b/classes/cluster/k8s_aio_calico/infra/config.yml
@@ -1,4 +1,4 @@
-alasses:
+classes:
 - system.linux.system.repo.ubuntu
 - system.openssh.client.lab
 - system.salt.master.pkg