fix merge signals

osf/models/user.py

@@ -864,7 +864,7 @@ def merge_user(self, user):
 
         user.save()
         signals.user_account_merged.send(user)
-        signals.user_account_deactivated.send(self)
+        signals.user_account_deactivated.send(user)
 
     def _merge_users_preprints(self, user):
         """