Fixed 9523 -- Restart runserver after compiling apps translations

Django also uses locales provided by apps, which also might change. Also when i18n is disabled, there is no need for watching translation files.

This complements commit 8b3d9d96ed8304d749c9056c42be89084d9b34aa and [refs #9523](https://code.djangoproject.com/ticket/9523).