Avoid warning for clone of field for running tests

[belugame]

Django clones fields (leads to re-init with forbidden kwargs) when running tests and that triggers the warning for no good reason. Not a perfect solution but at that scope it seems there is nothing else to determine a 2nd init.

[zsoldosp]

hmm, and there is an explicit test for it testapp.tests.CurrentUserFieldTestCase.test_warning_is_raised_when_forbidden_arguments_are_passed...

IIRC it also came up during migrations, where there was some workaround...

without having looked at the implementation, my initial ideas are

• check that the passed values match the default, and if so, don't raise
• I'm sure there is a way we could check whether the model in question has been initialized, and only raise this then - essentially, we want to prevent developer errors, and not django internals
• should it be converted to a system check?

2c only

[belugame]

Thank you for your suggestions and sorry, had to postphone this bit of work for while.

check that the passed values match the default, and if so, don't raise

That's a good idea, and probably the easiest solution too. I will add a new MR for that.