Fixed typo mistake in purging certain package 'unattended-upgrades'

Change-Id: I5fe981d121a7e4f436c42467ed50a192926a9cf7
diff --git a/linux/system/single/init.yml b/linux/system/single/init.yml
index 1e68380..8de2dda 100644
--- a/linux/system/single/init.yml
+++ b/linux/system/single/init.yml
@@ -17,7 +17,7 @@
       package:
         cloud-init:
           version: purged
-        unattended-updates:
+        unattended-upgrades:
           version: purged
         mcelog:
           version: latest