cmd: workaround conpty race condition in Start() - #2923

cmd: workaround conpty race condition in Start()#2923

mcayland-ntx wants to merge 1 commit into

microsoft:mainmicrosoft/hcsshim:mainfrom

mcayland-ntx:fix/avoid-conpty-race-with-no-stdinmcayland-ntx/hcsshim:fix/avoid-conpty-race-with-no-stdinCopy head branch name to clipboard