Bumped latest release to 4.6.20 (#356)

Author: mnocon

mkdocs.yml

@@ -190,7 +190,7 @@ extra:
 
   developer_doc: 'https://doc.ibexa.co/en/5.0'
 
-  latest_tag_4_6: '4.6.19'
+  latest_tag_4_6: '4.6.20'
 
 extra_css:
   - fonts/MavenPro.css