fixed a typo in make.conf.

Thanks to 菜鸟GGGGG [1]

[1]: http://www.baidu.com/p/%E8%8F%9C%E9%B8%9FGGGGG

--HG--
extra : amend_source : 9a2ca5abe57d1ec94febe64b0f1792f71adc2c6a