ensure that cfg.LogTo is properly closed on disconnect if its underlying type is a file

diamond.go

@@ -121,6 +121,9 @@ func (e *Engine) logSql(msg, sql string) {
 // Disconnect - closes and disposes of this Engine's connection pool.
 func (e *Engine) Disconnect() {
 	e.conn.Close()
+	if asFile, ok := e.cfg.LogTo.(*os.File); ok {
+		_ = asFile.Close()
+	}
 }
 
 // Open - creates a new connection according to `connString`