[provisioner-env-configuration] Fix example environment variables configuration

[gregth]

The example configuration for the environment variables in the documentation / README file has some typos:

   env:
   - name: NAMESPACE
     valueFrom:
        fieldRef:
        fieldPath: metadata.namespace
   - name: POD_NAME
     valueFrom:
        fieldRef:
        fieldPath: metadata.name

The fieldPath should be indented under the fieldRef:

    env:
    - name: NAMESPACE
      valueFrom:
-        fieldRef:
-        fieldPath: metadata.namespace
+       fieldRef:
+         fieldPath: metadata.namespace
    - name: POD_NAME
      valueFrom:
-        fieldRef:
-        fieldPath: metadata.name
+       fieldRef:
+         fieldPath: metadata.name