database: clean up PEP 8 warnings.

Turn a lambda into a def.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>

lib/newfol/database.py

@@ -562,7 +562,9 @@ class Database:
 
     def upgrade(self, txntype=None, notify=None, version=None):
         if notify is None:
-            notify = lambda x: x
+
+            def notify(x):
+                x
         if txntype is None:
             txntype = list(self._schema.transaction_types())
         elif isinstance(txntype, str):