Since https://github.com/odoo/odoo/commit/5a030db3eb77b6d80187f8ae1a64303b2f50391d
the HTML editor displayed the translated versions of the templates it
allows to customize. So if the user edited and saved such a template,
the non-translated version was saved with translated-version content.
The behavior before the mentioned commit was:
1) Load all views the HTML editor allows to edit
2) Each time a view is displayed, re-make a RPC to load the view again
The mentioned commit made this simpler by making:
1) Load all views the HTML editor allows to edit
2) Each time a view is displayed, simply show the previously loaded view
... the problem was that the step (2) of the old behavior was
explicitly saying (client-side) to load the view's untranslated content.
This commit makes step (1) always load the untranslated versions of the
views (server-side).