Enable social auth debug

We need to diagnose what goes wrong on the Selenium testsuite.
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/settings_example.py

@@ -199,6 +199,7 @@ SOCIAL_AUTH_PIPELINE = (
     'weblate.accounts.pipeline.verify_open',
     'social.pipeline.user.create_user',
     'social.pipeline.social_auth.associate_user',
+    'social.pipeline.debug.debug',
     'social.pipeline.social_auth.load_extra_data',
     'weblate.accounts.pipeline.user_full_name',
     'weblate.accounts.pipeline.store_email',