fix: migration file (#1453)

## 🔄 Changes Summary
- Set default value for `to_address` field

## 🔗 Related PRs
- #1452

Author: rachit77

bridgesync/migrations/bridgesync0013.sql

@@ -0,0 +1,7 @@
+-- +migrate Down
+ALTER TABLE bridge DROP COLUMN to_address;
+ALTER TABLE bridge ADD COLUMN to_address VARCHAR;
+
+-- +migrate Up
+ALTER TABLE bridge DROP COLUMN to_address;
+ALTER TABLE bridge ADD COLUMN to_address VARCHAR DEFAULT '';