[migration] handle the case where new final entity type is not yet in the schema
This may occur on new cube addition. Related to #7569998.
.. role:: raw-html(raw)
:format: html
RSS driven
----------
RSS is a pretty useful technology that can be widely used on this
site. Any set of data can be presented as RSS. You can then plug in
an RSS reader into that and follow the site activity. For example :
:raw-html:`<p><a class="reference"
href="../view?vid=rss&rql=Any+X%2CM+WHERE+X+modification_date+M+ORDERBY+M+DESC+LIMIT+30"><img
alt="rss" src="../data/rss.png"> latest changes</a></p>`