testrelease build does not validate the javadoc anymore

For example it did not catched https://github.com/xwiki/xwiki-commons/commit/da69b140bbc06993671763b1b2636ed88d73e75e.

I can see in the log that the javadoc is definitely built but looks like it's not validated anymore for some reason.

Discovering this kind of thing only during the release is quite a pain...