schema: allow empty lists in resource schema

Change-Id: I9249e29deef00d4dd68f89c704ef1d3093c799fd
diff --git a/src/osmo_gsm_tester/core/schema.py b/src/osmo_gsm_tester/core/schema.py
index 816f439..9d26b0f 100644
--- a/src/osmo_gsm_tester/core/schema.py
+++ b/src/osmo_gsm_tester/core/schema.py
@@ -307,7 +307,7 @@
             if util.is_dict(value):
                 nest(path, value, schema)
                 return
-            if util.is_list(value) and value:
+            if util.is_list(value):
                 for list_v in value:
                     validate_item(path, list_v, schema)
                 return