Fix offline layer name

Author: m-kuhn

src/core/qgsofflineediting.cpp

@@ -636,7 +636,7 @@ QgsVectorLayer *QgsOfflineEditing::copyVectorLayer( QgsVectorLayer *layer, sqlit
       char **options = nullptr;
 
       options = CSLSetNameValue( options, "OVERWRITE", "YES" );
-      options = CSLSetNameValue( options, "IDENTIFIER", layer->name().toUtf8().constData() );
+      options = CSLSetNameValue( options, "IDENTIFIER", tr( "%1 (offline)" ).arg( layer->name() ).toUtf8().constData() );
       options = CSLSetNameValue( options, "DESCRIPTION", layer->dataComment().toUtf8().constData() );
 #if 0
       options = CSLSetNameValue( options, "FID", featureId.toUtf8().constData() );