Edited YAML for 5-1 kuard pod

The indentation for ' spec' wasn't correct and this wouldn't deploy. The indentation in the book itself is correct. I changed it to a working deployment.

FYI: this was the error I got with the initial deployment: 
error: error validating "test-with-space.yaml": error validating data: ValidationError(Pod.metadata): unknown field "spec" in io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta; if you choose to ignore these errors, turn validation off with --validate=false

5-1-kuard-pod.yaml

@@ -2,7 +2,7 @@ apiVersion: v1
 kind: Pod
 metadata:
   name: kuard
-  spec:
+spec:
   containers:
   - image: gcr.io/kuar-demo/kuard-amd64:1
     name: kuard