Update vulnerabilities/importer.py

Co-authored-by: Philippe Ombredanne <pombredanne@gmail.com>

Author: Hritik14

vulnerabilities/importer.py

@@ -229,7 +229,7 @@ def __init__(self):
             raise Exception(f"Cannot run importer {self!r} without a license")
 
     @classproperty
-    def qualified_name(self):
+    def qualified_name(cls):
         """
         Fully qualified name prefixed with the module name of the improver used in logging.
         """