Dockerfile: update docker.
Dockerfile: update docker.

c4pt0r/tidb,qiuyesuifeng/tidb,pingcap/tidb,kyle-wang/tidb,yuanwhy/tidb,simon-xia/tidb,kyle-wang/tidb,EvilMcJerkface/tidb,c4pt0r/tidb,spongedu/tidb,cosmtrek/tidb,yuanwhy/tidb,louishust/tidb,zimulala/tidb,astaxie/tidb,c4pt0r/tidb,pingcap/tidb,kyle-wang/tidb,louishust/tidb,wusphinx/tidb,coocood/tidb,ueizhou/tidb,tiancaiamao/tidb,XuHuaiyu/tidb,ngaut/tidb,8cbx/tidb,pingcap/tidb,pingcap/tidb,yangwenmai/tidb,Cofyc/tidb,pingcap/tidb,8cbx/tidb,silentred/tidb,simon-xia/tidb,ngaut/tidb,c4pt0r/tidb,ueizhou/tidb,gaocegege/tidb,Cofyc/tidb,ming-relax/tidb,coocood/tidb,anywhy/tidb,CodeRushing/tidb,silentred/tidb,wusphinx/tidb,astaxie/tidb,qhsong/tidb,kyle-wang/tidb,pingcap/tidb,mccxj/tidb,XuHuaiyu/tidb,qhsong/tidb,kyle-wang/tidb,zs634134578/tidb,andelf/tidb,c4pt0r/tidb,spongedu/tidb,JinheLin/tidb,zimulala/tidb,gaocegege/tidb,tiancaiamao/tidb,yangwenmai/tidb,silenceper/tidb,ngaut/tidb,mccxj/tidb,cosmtrek/tidb,EvilMcJerkface/tidb,liyu4/tidb,kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb,andelf/tidb,ngaut/tidb,anywhy/tidb,JinheLin/tidb,zs634134578/tidb,liyu4/tidb,Nify/tidb,myrice/tidb,myrice/tidb,CodeRushing/tidb,ngaut/tidb,qiuyesuifeng/tidb,Nify/tidb,ming-relax/tidb,silenceper/tidb