executor: fix example

Author: Morg42

executor/examples/database_series.py

@@ -1,9 +1,9 @@
 import json
 
 def myconverter(o):
-import datetime
-if isinstance(o, datetime.datetime):
-  return o.__str__()
+  import datetime
+  if isinstance(o, datetime.datetime):
+    return o.__str__()
 data = sh.<your item here>.series('max','1d','now')
 pretty = json.dumps(data, default = myconverter, indent = 2, separators=(',', ': '))
 print(pretty)