Add ascii parser flag
Add ascii parser flag

Summary: This flag was accidentally removed by D1952690

Test Plan: tests

Reviewed By: @andriigrynenko

Differential Revision: D1970841
glensc/mcrouter,nvaller/mcrouter,synecdoche/mcrouter,leitao/mcrouter,facebook/mcrouter,facebook/mcrouter,nvaller/mcrouter,easyfmxu/mcrouter,reddit/mcrouter,zhlong73/mcrouter,evertrue/mcrouter,is00hcw/mcrouter,apinski-cavium/mcrouter,synecdoche/mcrouter,zhlong73/mcrouter,evertrue/mcrouter,synecdoche/mcrouter,reddit/mcrouter,glensc/mcrouter,apinski-cavium/mcrouter,zhlong73/mcrouter,leitao/mcrouter,is00hcw/mcrouter,tempbottle/mcrouter,yqzhang/mcrouter,tempbottle/mcrouter,yqzhang/mcrouter,easyfmxu/mcrouter,easyfmxu/mcrouter,synecdoche/mcrouter,yqzhang/mcrouter,glensc/mcrouter,reddit/mcrouter,nvaller/mcrouter,nvaller/mcrouter,zhlong73/mcrouter,yqzhang/mcrouter,glensc/mcrouter,apinski-cavium/mcrouter,leitao/mcrouter,facebook/mcrouter,leitao/mcrouter,tempbottle/mcrouter,easyfmxu/mcrouter,apinski-cavium/mcrouter,reddit/mcrouter,facebook/mcrouter,tempbottle/mcrouter,is00hcw/mcrouter,evertrue/mcrouter,evertrue/mcrouter,is00hcw/mcrouter