UI: Fix scene collection importer OS translation

The OS translation in the Scene Collection Importer seems to have been
broken since the feature was added because the translated sources were
not added back to the output JSON object. Add the translated sources to
the output JSON object to get the feature to work.

UI/importers/studio.cpp

@@ -143,6 +143,7 @@ void TranslateOSStudio(Json &res)
 #undef ClearTranslation
 	}
 
+	out["sources"] = sources;
 	res = out;
 }