Fix flake8 E231 reported linting failure

Author: jfbu

sphinx/builders/linkcheck.py

@@ -65,7 +65,7 @@ def finish(self) -> None:
 
         output_text = path.join(self.outdir, 'output.txt')
         output_json = path.join(self.outdir, 'output.json')
-        with open(output_text, 'w', encoding='utf-8') as self.txt_outfile,\
+        with open(output_text, 'w', encoding='utf-8') as self.txt_outfile, \
              open(output_json, 'w', encoding='utf-8') as self.json_outfile:
             for result in checker.check(self.hyperlinks):
                 self.process_result(result)

tests/test_build_linkcheck.py

@@ -782,7 +782,7 @@ def test_too_many_requests_retry_after_HTTP_date(app, capsys):
 
 @pytest.mark.sphinx('linkcheck', testroot='linkcheck-localserver', freshenv=True)
 def test_too_many_requests_retry_after_without_header(app, capsys):
-    with http_server(make_retry_after_handler([(429, None), (200, None)])),\
+    with http_server(make_retry_after_handler([(429, None), (200, None)])), \
          mock.patch("sphinx.builders.linkcheck.DEFAULT_DELAY", 0):
         app.build()
     content = (app.outdir / 'output.json').read_text(encoding='utf8')