fix copy pasta from package to plugin

Signed-off-by: pstlouis <patrick.st-louis@opsecid.ca>

aries_cloudagent/config/default_context.py

@@ -123,7 +123,7 @@ async def load_plugins(self, context: InjectionContext):
         plugin_registry.register_plugin("aries_cloudagent.holder")
 
         if not self.settings.get("ledger.disabled"):
-            plugin_registry.register_package("aries_cloudagent.ledger")
+            plugin_registry.register_plugin("aries_cloudagent.ledger")
 
         plugin_registry.register_plugin("aries_cloudagent.messaging.jsonld")
         plugin_registry.register_plugin("aries_cloudagent.resolver")