Fix error with translation unlinking.

Author: robgietema

CHANGELOG.md

@@ -180,6 +180,7 @@
 - Fix issue with layouts in types endpoint @robgietema
 - Fix issue with sharing @robgietema
 - Narrow down the `config.blobs` type to only allow 'file' or 'db' @sneridagh
+- Fix error with translation unlinking @robgietema
 
 ### Internal
 

src/routes/translations/translations.ts

@@ -66,7 +66,7 @@ export default [
       );
       await document.update(
         {
-          translation_group: null,
+          translation_group: document.uuid,
         },
         trx,
       );