[1.7.x] Only warn about initial data if fixtures have been found.

        if fixture_name != 'initial_data' and not fixture_files:

            # Warning kept for backwards-compatibility; why not an exception?

            warnings.warn("No fixture named '%s' found." % fixture_name)

        elif fixture_name == 'initial_data':

        elif fixture_name == 'initial_data' and fixture_files:

            warnings.warn(

                'initial_data fixtures are deprecated. Use data migrations instead.',

                RemovedInDjango19Warning