fixing Sequential.remove corner case
fixing Sequential.remove corner case

sagarwaghmare69/nn,bartvm/nn,lvdmaaten/nn,sbodenstein/nn,noa/nn,Djabbz/nn,abeschneider/nn,ominux/nn,andreaskoepf/nn,colesbury/nn,EnjoyHacking/nn,ivendrov/nn,Aysegul/nn,jzbontar/nn,adamlerer/nn,eulerreich/nn,diz-vara/nn,rotmanmi/nn,mlosch/nn,lukasc-ch/nn,vgire/nn,forty-2/nn,clementfarabet/nn,GregSatre/nn,joeyhng/nn,witgo/nn,xianjiec/nn,apaszke/nn,Moodstocks/nn,hughperkins/nn,Jeffyrao/nn,nicholas-leonard/nn,zhangxiangxiao/nn,aaiijmrtt/nn,PierrotLC/nn,PraveerSINGH/nn,LinusU/nn,elbamos/nn,caldweln/nn,jhjin/nn,eriche2016/nn,davidBelanger/nn,kmul00/nn,jonathantompson/nn,douwekiela/nn