api.py missing import of datetime causes trac-admin upgrade to fail

[Bobby]

Running the upgrade with trac-admin after adding the plugin kept failing, and in trac.log it said the api portion of the plugin had undefined datetime.
I noticed all .py of the plugin were importing datetime except api.py. Adding to api.py

from datetime import datetime

made the upgrade work and now I can use the plugin. I'm not sure why no one else has reported this error, and I doubt there's anything unusual in how my system is configured.

[rjollos]

(In [12358]) Fixes #10628 : Added missing import of datetime in api.py. Thanks to Bobby for the patch.