[minor] if address is not found then set the address_field to '' instead of None
diff --git a/erpnext/public/js/utils/party.js b/erpnext/public/js/utils/party.js
index d132f92..19fe277 100644
--- a/erpnext/public/js/utils/party.js
+++ b/erpnext/public/js/utils/party.js
@@ -90,7 +90,7 @@
 			}
 		})
 	} else {
-		frm.set_value(display_field, null);
+		frm.set_value(display_field, '');
 	}
 };