style(database/postgres.go): Capitalize DSN in comment (#3993)

Signed-off-by: yxxhero <aiopsclub@163.com>

Author: yxxhero

manager/database/postgres.go

@@ -31,7 +31,7 @@ import (
 func newPostgres(cfg *config.Config) (*gorm.DB, error) {
 	postgresCfg := &cfg.Database.Postgres
 
-	// Format dsn string.
+	// Format DSN string.
 	dsn := formatPostgresDSN(postgresCfg)
 
 	// Connect to postgres.