oracle分页，start 为 0 的bug (#2098)

删除前面判断即可。

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-on: https://gitea.com/xorm/xorm/pulls/2098
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: fuge <fuge@noreply.gitea.io>
Co-committed-by: fuge <fuge@noreply.gitea.io>

internal/statements/query.go

@@ -334,7 +334,7 @@ func (statement *Statement) genSelectSQL(columnStr string, needLimit, needOrderB
 				fmt.Fprint(&buf, " LIMIT ", *pLimitN)
 			}
 		} else if dialect.URI().DBType == schemas.ORACLE {
-			if statement.Start != 0 && pLimitN != nil {
+			if pLimitN != nil {
 				oldString := buf.String()
 				buf.Reset()
 				rawColStr := columnStr