Moving - to _

Change-Id: I1f66df5b3b40dfa44b3a5df40ee7c683bb097f45
(cherry picked from commit 9b849eb1ee572089800fda87d9cb26b73d8d13eb)
diff --git a/group_vars/all b/group_vars/all
index ce534be..4dd0349 100644
--- a/group_vars/all
+++ b/group_vars/all
@@ -110,4 +110,4 @@
 
 frontend_only: False
 
-xos_services: []
\ No newline at end of file
+xos_services: []