examples sklearn_text_classifier model.py get project_id error

[yangzhouhu]

label-studio-ml-backend examples sklearn_text_classifier model.py function fit(self, event, data, **kwargs):
The error in obtaining the variable 'project_id' at line 165 :

× project_id = data['annotation']['project']
│
╰─> should be change to : project_id = data['project']['id']

[ginic]

I have put up a pull request that I believe should fix this at #790