The specified autopkgtest control file is considered obsolete.
Before autodep8 version 0.17 and autopkgtest version 5.7 if a maintainer wished to add tests to the set of tests generated by autodep8 they provided those tests in a file named debian/tests/control.autodep8.
It is now prefered to declare the additional tests in the regular debian/tests/control file so that dpkg-source can pick up the test dependencies.
When configured to run autodep8 tests, autopkgtest will run the additional tests and the autodep8 tests when debian/control has the proper Testsuite: autopkgtest-* in the source headers.
Please merge the specified file into debian/tests/control.
Refer to the autodep8(1) manual page for details.