correct for unused import
@@ -24,7 +24,6 @@ from docutils.parsers.rst.directives import register_directive
from docutils.parsers.rst.directives.body import CodeBlock
from docutils.parsers.rst.directives.images import Image
from docutils.parsers.rst.directives.misc import Include, Raw
-from sphinx.application import Sphinx
from sphinx.util import logging
from gammapy.analysis import AnalysisConfig
