Fix ignore_overwritten_missing_reference default

Fixes: https://github.com/salt-formulas/reclass/issues/77

Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
diff --git a/reclass/settings.py b/reclass/settings.py
index b7f5252..62af976 100644
--- a/reclass/settings.py
+++ b/reclass/settings.py
@@ -39,7 +39,7 @@
             defaults.OPT_IGNORE_CLASS_NOTFOUND_REGEXP,
         'ignore_class_notfound_warning':
             defaults.OPT_IGNORE_CLASS_NOTFOUND_WARNING,
-        'ignore_overwritten_missing_referencesdefaults.':
+        'ignore_overwritten_missing_references':
             defaults.OPT_IGNORE_OVERWRITTEN_MISSING_REFERENCES,
         'group_errors': defaults.OPT_GROUP_ERRORS,
         'compose_node_name': defaults.OPT_COMPOSE_NODE_NAME,