Set IsBare true if migrated repo is empty.
Set IsBare true if migrated repo is empty.

Executes `git log -1` and sets IsBare to true if stderr contains this
string:

  fatal: bad default revision 'HEAD'

pentix/gogs,cem/gogs,kubatyszko/gitea,kolonse/gogs,gigforks/gogs,geek1011/gitea,spacetourist/gitea,svcavallar/gogs,haoyixin/gogs,mark77z/tt2016,cez81/gitea,everhopingandwaiting/gogs,everhopingandwaiting/gogs,cez81/gitea,mjwwit/gitea,avelino/gitea,xaionaro/gogs,gemili/gogs,0rax/gogs,Spice-King/gogs,pentix/gogs,tszym/gogs,geek1011/gitea,tanapoln/gogs,gogits/gogs,sapk-fork/gitea,lunny/gitea,tony/gogs,jqs7/gogs,pwelter34/gogs,AndreaGiardini/gogs,kubatyszko/gitea,cgars/gogs,andreynering/gitea,kjellkvinge/gitea,codeskyblue/gogs,xet7/gogs,SlavikZ/gogs,mpindado/gogs,psaavedra/gogs,tboerger/gitea,tanapoln/gogs,hiproz/gogs,mark77z/tt2016,bygreencn/gogs,AndreaGiardini/gogs,jvanderneutstulen/gogs,xiaoyanit/gogs,lafriks/gitea,tony/gogs,kong36088/SCAUGogits,kolonse/gogs,xet7/gogs,sapk/gogs,sapk-fork/gitea,wangjild/gogs,mapmeld/codemingler,opavader/gogs,dlob/gogs,denji/gitea_tmp,pentix/gogs,SlavikZ/gogs,huyueMiss/gogs,manfer/gogs,cybe/gitea,linquize/gogs,kong36088/SCAUGogits,dancewing/gogs,Bwko/gitea,gogits/gogs,kiliit/gogs,andrewrothstein/gogs,andrewrothstein/gogs,gigforks/gogs,vCaesar/gitea,huyueMiss/gogs,svcavallar/gogs,AndreaGiardini/gogs,mjwwit/gitea,xaionaro/gogs,haoyixin/gogs,denji/gitea_tmp,cumgun/gitea,pikacloud/pikacode,psaavedra/gogs,psolyca/gitea,jqs7/gogs,0rax/gogs,denji/gitea,beni55/gogs,denji/gitea_tmp,Morlinest/gitea,sapk/gogs,vdbt/gitea,go-gitea/gitea,liliexuan/gogs,xaionaro/gogs,dnmgns/gitea,sillydong/gogs,xet7/gogs,bygreencn/gogs,Spice-King/gogs,0rax/gogs,Bwko/gitea,cybe/gitea,mpindado/gogs,opavader/gogs,denghongcai/gogs,psaavedra/gogs,xiaoyanit/gogs,CaeruleusAqua/gitea,ForxaCoLab/forxa,wangjild/gogs,Morlinest/gitea,gwynantj/gogs,Bwko/gitea,ethantkoenig/gitea,opavader/gogs,rems4e/gitea,dnmgns/gitea,xiaoyanit/gogs,cez81/gitea,jacobxk/gogs,ethantkoenig/gogs,cem/gogs,ForxaCoLab/forxa,Janfred/gogs,jorgesumle/gitea,JonasFranzDEV/gitea,gigforks/gogs,richmahn/gogs,geerlingguy/gogs,SlavikZ/gogs,geerlingguy/gogs,treejames/gogs,lunny/gitea,lunny/gitea,everhopingandwaiting/gogs,strk/gogs,jorgesumle/gitea,cgars/gogs,geerlingguy/gogs,CaeruleusAqua/gitea,svcavallar/gogs,Spice-King/gogs,avelino/gitea,lafriks/gitea,gogits/gogs,Janfred/gogs,typeless/gitea,minecrafter/gitea,kjellkvinge/gitea,vCaesar/gitea,typeless/gitea,willemvd/gitea,GodOfConquest/gogs,richmahn/gogs,sillydong/gogs,jvanderneutstulen/gogs,bkcsoft/gogs,kubatyszko/gitea,codeskyblue/gogs,likeit92/gogs,sapk/gogs,jvanderneutstulen/gogs,pikacloud/pikacode,cgars/gogs,tszym/gogs,ForxaCoLab/forxa,mukaiu/gogs,mukaiu/gogs,gemili/gogs,denghongcai/gogs,avelino/gitea,gemili/gogs,linquize/gogs,chriswatt/gogs,odinuge/gogs,dlob/gogs,GodOfConquest/gogs,kiliit/gogs,kong36088/SCAUGogits,Janfred/gogs,lafriks/gitea,puffybsd/gitea,typeless/gitea,gwynantj/gogs,w4ngyi/gogs,odinuge/gogs,liliexuan/gogs,treejames/gogs,go-gitea/gitea,ethantkoenig/gogs,w4ngyi/gogs,kolonse/gogs,everhopingandwaiting/gogs,cem/gogs,chriswatt/gogs,sillydong/gogs,GodOfConquest/gogs,mapmeld/codemingler,mpindado/gogs,sapk-fork/gitea,strk/gogs,admik/gitea,pwelter34/gogs,tszym/gogs,bygreencn/gogs,jacobxk/gogs,denghongcai/gogs,gwynantj/gogs,mapmeld/codemingler,treejames/gogs,andreynering/gitea,andrewrothstein/gogs,sapk-fork/gitea,dancewing/gogs,psolyca/gitea,0rax/gogs,chriswatt/gogs,tempbottle/gogs,kjellkvinge/gitea,pikacloud/pikacode,manfer/gogs,avelino/gitea,tboerger/gitea,tanapoln/gogs,manfer/gogs,bkcsoft/gogs,jqs7/gogs,linquize/gogs,dnmgns/gitea,kiliit/gogs,pwelter34/gogs,liliexuan/gogs,tboerger/gitea,tempbottle/gogs,cumgun/gitea,rems4e/gitea,hiproz/gogs,go-gitea/gitea,tempbottle/gogs,beni55/gogs,dancewing/gogs,haoyixin/gogs,likeit92/gogs,odinuge/gogs,wangjild/gogs,beni55/gogs,bkcsoft/gogs,spacetourist/gitea,typeless/gitea,makhov/gitea,mukaiu/gogs,likeit92/gogs,dancewing/gogs,xormplus/gitea,mark77z/tt2016,w4ngyi/gogs,DblK/gitea,dl5rcw/gitea,denji/gitea_tmp,huyueMiss/gogs,dlob/gogs,strk/gogs,jacobxk/gogs,JonasFranzDEV/gitea,DblK/gitea,hiproz/gogs,tony/gogs,codeskyblue/gogs,gigforks/gogs,ethantkoenig/gitea,vdbt/gitea