fix migrations

migrations/000020_alter_files_table_transcode.down.sql

@@ -1,4 +1,4 @@
-ALTER TABLE tasks
+ALTER TABLE files
 DROP IF EXISTS old_md5,
 DROP IF EXISTS old_ffprobe_data,
-DROP IF EXISTS old_size bigint;
+DROP IF EXISTS old_size;

migrations/000020_alter_files_table_transcode.up.sql

@@ -1,4 +1,3 @@
-ALTER TABLE libraries
-ADD old_md5 uuid,
+ALTER TABLE files ADD old_md5 uuid,
 ADD old_ffprobe_data JSONB,
 ADD old_size bigint;