readthedocs: pin theme to sphinx_rtd_theme

ReadTheDocs changed the default theme.

diff --git a/doc/userguide/conf.py b/doc/userguide/conf.py
index 47fec8ec6c24e83a9960da9f29779d3ff7ed0ae4..cf87f19c311eb37d7ec35419463d7475f79ad4ff 100644 (file)
--- a/doc/userguide/conf.py
+++ b/doc/userguide/conf.py
@@ -143,6 +143,7 @@ if not on_rtd:
         else:
             app.add_stylesheet('css/suricata.css')
 else:
+    html_theme = 'sphinx_rtd_theme'
     html_context = {
         'css_files': [
             'https://media.readthedocs.org/css/sphinx_rtd_theme.css',