Downgrade to version 2.6.7
sjis.c, gb18030.c gb2312.c are parts of LIBICONV
opensource with GPL-2.0 license. It was added after 2.6.7 so
downgrade to 2.7.1 to 2.6.7.
Current version is corresponding to
```
commit
385a0a246f2d9f7a6fd774fd8edc03d3d965f49e (HEAD)
Author: Robin Stuart <rstuart114@gmail.com>
Date: Sun Nov 17 22:03:54 2019 +0000
typo-- in isotest
```
Change-Id: If90b5f00e9db5fcf94a895b9fef8afea0f43cfd8
Signed-off-by: Tae-Young Chung <ty83.chung@samsung.com>