Handle empty repoID and print error, fixes #11
Handle empty repoID and print error, fixes #11

CN-Sean/gitbook,tzq668766/gitbook,hujianfei1989/gitbook,snowsnail/gitbook,sunlianghua/gitbook,minghe/gitbook,haamop/documentation,xxxhycl2010/gitbook,codepiano/gitbook,grokcoder/gitbook,wewelove/gitbook,2390183798/gitbook,GitbookIO/gitbook,youprofit/gitbook,JozoVilcek/gitbook,ferrior30/gitbook,sudobashme/gitbook,gdbooks/gitbook,xiongjungit/gitbook,qingying5810/gitbook,mautic/documentation,nycitt/gitbook,tshoper/gitbook,ShaguptaS/gitbook,yaonphy/SwiftBlog,escopecz/documentation,sudobashme/gitbook,vehar/gitbook,OriPekelman/gitbook,2390183798/gitbook,OriPekelman/gitbook,lucciano/gitbook,escopecz/documentation,ZachLamb/gitbook,xcv58/gitbook,ryanswanson/gitbook,hongbinz/gitbook,jocr1627/gitbook,vehar/gitbook,ferrior30/gitbook,boyXiong/gitbook,jasonslyvia/gitbook,bjlxj2008/gitbook,thelastmile/gitbook,gencer/gitbook,minghe/gitbook,megumiteam/documentation,tzq668766/gitbook,shibe97/gitbook,xiongjungit/gitbook,jasonslyvia/gitbook,tshoper/gitbook,iflyup/gitbook,codepiano/gitbook,snowsnail/gitbook,bradparks/gitbook,qingying5810/gitbook,webwlsong/gitbook,gaearon/gitbook,iamchenxin/gitbook,FKV587/gitbook,justinleoye/gitbook,palerdot/gitbook,hongbinz/gitbook,thelastmile/gitbook,intfrr/gitbook,athiruban/gitbook,lucciano/gitbook,megumiteam/documentation,ShaguptaS/gitbook,webwlsong/gitbook,nycitt/gitbook,sunlianghua/gitbook,mruse/gitbook,FKV587/gitbook,Keystion/gitbook,haamop/documentation,gaearon/gitbook,bradparks/gitbook,npracht/documentation,alex-dixon/gitbook,rohan07/gitbook,ZachLamb/gitbook,CN-Sean/gitbook,strawluffy/gitbook,rohan07/gitbook,xxxhycl2010/gitbook,Abhikos/gitbook,a-moses/gitbook,switchspan/gitbook,mautic/documentation,wewelove/gitbook,intfrr/gitbook,iflyup/gitbook,switchspan/gitbook,boyXiong/gitbook,svenkatreddy/gitbook,mruse/gitbook,shibe97/gitbook,alex-dixon/gitbook,xcv58/gitbook,JohnTroony/gitbook,iamchenxin/gitbook,kamyu104/gitbook,anrim/gitbook,svenkatreddy/gitbook,youprofit/gitbook,a-moses/gitbook,JohnTroony/gitbook,gencer/gitbook,grokcoder/gitbook,jocr1627/gitbook,athiruban/gitbook,hujianfei1989/gitbook,bjlxj2008/gitbook,justinleoye/gitbook,gdbooks/gitbook,kamyu104/gitbook,npracht/documentation,guiquanz/gitbook,palerdot/gitbook,guiquanz/gitbook