Make XOS DB service name consistent with a hyphen

Change-Id: I034645651f01335199d0ad847487a8d2fca2cbf6
diff --git a/xos/xos/settings.py b/xos/xos/settings.py
index 4be97b1..1661cfc 100644
--- a/xos/xos/settings.py
+++ b/xos/xos/settings.py
@@ -53,7 +53,7 @@
         'NAME': Config.get('database.name'),
         'USER': Config.get('database.username'),
         'PASSWORD': Config.get('database.password'),
-        'HOST': "xos_db",
+        'HOST': "xos-db",
         'PORT': 5432,
     }
 }