Fix custom translator setup

Programmatically setting html_translator_class is apparently broken in
Sphinx 1.5 (which sorta makes sense, it's a bit of a hack, I'm not sure
why we even did that instead of going through the configuration object).

_extensions/odoo/__init__.py

@@ -8,6 +8,9 @@ import sphinx.environment
 import sphinx.builders.html
 from docutils import nodes
 def setup(app):
+    if hasattr(app, 'set_translator'):
+        app.set_translator('html', translator.BootstrapTranslator)
+    else:
         if getattr(app.config, 'html_translator_class', None):
             app.warn("Overriding the explicitly set  html_translator_class setting",
                      location="odoo extension")