ProjectStore.initIfNecessary has a tiny risk of losing data

[WULCAN]

On e5d3297, ProjectStore.initIfNecessary implements lazy-initialization of languages. While we await getTranslations, other invocations can enter initIfNecessary. As we are still waiting, the new invocations will find languages empty and start their own initialization.

Concurrent getTranslations are non-problematic but overwriting languages is worse. If getTranslation was very slow, translators might already have made changes to languages before the last initializing invocation writes languages. Then those changes will be lost.

As long as getTranslations is not extremely slow, the risk of losing work like this remains very low.