fix bugs

migrations/postgres/02105_node.sql

@@ -1,4 +1,3 @@
--- migrate:up
 CREATE TABLE IF NOT EXISTS "servers" (
     "id" BIGINT GENERATED BY DEFAULT AS IDENTITY NOT NULL,
     "name" varchar(100)  NOT NULL DEFAULT '',
@@ -27,7 +26,3 @@ CREATE TABLE IF NOT EXISTS "nodes" (
     PRIMARY KEY ("id")
 );
 
--- migrate:down
-DROP TABLE IF EXISTS "nodes";
-DROP TABLE IF EXISTS "servers";
-