Check if tty is nil in handler
Check if tty is nil in handler

Signed-off-by: Michael Crosby <951f4c7b5d47e32d0112c78d14a98eaa23e6b5ef@gmail.com>

nkwilson/runc,adrianreber/runc,hqhq/runc,sunyuan3/runc,nkwilson/runc,wangkirin/runc,jhowardmsft/runc,opencontainers/runc,keloyang/runc,crosbymichael/runc,jhowardmsft/runc,vbatts/runc,rhatdan/runc,avagin/runc,rajasec/runc,wangkirin/runc,rhatdan/runc,ZJU-SEL/runc,laijs/runc,wking/runc,abduld/runc,cloudfoundry-incubator/runc,kolyshkin/runc,rajasec/runc,dqminh/runc,inatatsu/runc,WeiZhang555/runc,maxamillion/runc,runcom/runc,justincormack/runc,sunyuan3/runc,mYmNeo/runc,mikebrow/runc,hqhq/runc,sunyuan3/runc,keloyang/runc,shishir-a412ed/runc,albertoleal/runc,crosbymichael/runc,cloudfoundry-incubator/runc,docker/runc,wangkirin/runc,ZJU-SEL/runc,opencontainers/runc,justincormack/runc,mYmNeo/runc,docker/runc,coolljt0725/runc,inatatsu/runc,vbatts/runc,adrianreber/runc,stefanberger/runc,cyphar/runc,estesp/runc,WeiZhang555/runc,hqhq/runc,xiaochenshen/runc,justincormack/runc,wking/runc,maxamillion/runc,mikebrow/runc,mikebrow/runc,kolyshkin/runc,rajasec/runc,runcom/runc,kolyshkin/runc,runcom/runc,dqminh/runc,dqminh/runc,avagin/runc,ZJU-SEL/runc,opencontainers/runc,cyphar/runc,maxamillion/runc,stefanberger/runc,albertoleal/runc,vbatts/runc,mheon/runc,rhatdan/runc,avagin/runc,WeiZhang555/runc,estesp/runc,opencontainers/runc,abduld/runc,crosbymichael/runc,coolljt0725/runc,laijs/runc,jhowardmsft/runc,cloudfoundry-incubator/runc,cyphar/runc,dqminh/runc,shishir-a412ed/runc,kolyshkin/runc,nkwilson/runc,mheon/runc,rhatdan/runc,abduld/runc,albertoleal/runc,mheon/runc,keloyang/runc,wking/runc,estesp/runc,stefanberger/runc,shishir-a412ed/runc,xiaochenshen/runc,mYmNeo/runc,coolljt0725/runc,inatatsu/runc,xiaochenshen/runc,docker/runc,adrianreber/runc,laijs/runc