Remove config from docs as sphinx says it's misspelled.

Author: tim-schilling

docs/changes.rst

@@ -5,7 +5,7 @@ Serializable (don't include in main)
 ------------------------------------
 
 * Defines the ``BaseStore`` interface for request storage mechanisms.
-* Added the config setting ``TOOLBAR_STORE_CLASS`` to configure the request
+* Added the setting ``TOOLBAR_STORE_CLASS`` to configure the request
   storage mechanism. Defaults to ``debug_toolbar.store.MemoryStore``.