migrate --check still emits signals if database is up to date

[Jacob Walls]

pre_migrate and post_migrate signals are emitted for migrate --check, but only if the database is up-to-date.

A related side effect is that the logs also look like a like a real run, as it says "Operations to perform:" and "Running migrations:". The last sentence clarifies that nothing has been applied, but there is still the potential for a half-second of "what have I just done?".

% python manage.py migrate --check          
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions, social_django
Running migrations:
  No migrations to apply.

[JunKi Yoon]

Replying to Jacob Walls:

Can I try this ticket?

[JunKi Yoon]

I added patch :)
​PR