ssh: Fix salt deprecation warning.

  The 'gid_from_name' argument in the user.present state has been
  replaced with 'usergroup'.

Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>

ssh/init.sls

@@ -43,7 +43,7 @@ ssh-{{ user }}:
     - shell: /bin/bash
     - home: {{ path }}
     - createhome: True
-    - gid_from_name: True
+    - usergroup: True
     - system: False
 
 {# Create .ssh dir #}