Don't try to remove .repo if it doesn't exist
Don't try to remove .repo if it doesn't exist

Part of the cleanup path for _Init is removing the .repo
directory. However, _Init can fail before creating the .repo directory,
so trying to remove it raises another exception:

    fatal: invalid branch name 'refs/changes/53/55053/4'
    Traceback (most recent call last):
      File "/home/mitchelh/bin/repo", line 775, in <module>
        main(sys.argv[1:])
      File "/home/mitchelh/bin/repo", line 749, in main
        os.rmdir(repodir)
    OSError: [Errno 2] No such file or directory: '.repo'

Fix this by only removing .repo if it actually exists.

Change-Id: Ia251d29e9c73e013eb296501d11c36263457e235

gabbayo/git-repo,wzhy90/git-repo,daimajia/git-repo,xin3liang/git-repo,4455jkjh/repo,nuclearmistake/repo,couchbasedeps/git-repo,Pivosgroup/google-git-repo,kdavis-mozilla/repo-repo,IbpTeam/repo,CyanogenMod/tools_repo,iAlios/git-repo,FlymeOS/repo,TheQtCompany/git-repo,lipro-yocto/git-repo,ChronoMonochrome/repo,jingyu/git-repo,aosp-mirror/tools_repo,eligoenergy/git-repo,qioixiy/git-repo,petemoore/git-repo,kangear/git-repo,venus-solar/git-repo,biaolv/git-repo,xianyo/git-repo,windyan/git-repo,RuanJG/git-repo,wzhy90/git-repo,jingyu/git-repo,FuangCao/git-repo,simbasailor/git-repo,chenzilin/git-repo,testbetta/git-repo-pub,FuangCao/repo,chzhong/git-repo,TheQtCompany/git-repo,qupai/git-repo,eligoenergy/git-repo,DavidPu/git-repo,lshain/repo,IbpTeam/repo,gbraad/git-repo,linuxdeepin/git-repo,flingone/git-repo,mer-tools/git-repo,mozilla/git-repo,simbasailor/git-repo,windyan/git-repo,couchbasedeps/git-repo,lipro-yocto/git-repo,mer-tools/git-repo,GatorQue/git-repo-flow,ronan22/repo,testbetta/git-repo-pub,GerritCodeReview/git-repo,zemug/repo,chenzilin/git-repo,qioixiy/git-repo,FlymeOS/repo,llg84/google_repo,11NJ/git-repo,derron/git-repo,GerritCodeReview/git-repo,mozilla/git-repo,derron/git-repo,darrengarvey/git-repo,llg84/google_repo,ediTLJ/git-repo,Pivosgroup/google-git-repo,frogbywyplay/git-repo,hacker-camp/google_repo,DavidPu/git-repo,kdavis-mozilla/repo-repo,demonyangyue/git-repo,frogbywyplay/git-repo,ronan22/repo,mixedpuppy/git-repo,dodocat/git-repo,darrengarvey/git-repo,xecle/git-repo,FuangCao/repo,jcfrank/myrepo,demonyangyue/git-repo,xyyangkun/git-repo,lightsofapollo/git-repo,testbetta/repo-pub,qupai/git-repo,wavecomp/git-repo,iAlios/git-repo,gbraad/git-repo,xin3liang/git-repo,ceejatec/git-repo,testbetta/repo-pub,opencontrail-ci-admin/git-repo,venus-solar/git-repo,petemoore/git-repo,codetutil/git-repo,lewixliu/git-repo,lshain/repo,wavecomp/git-repo,xyyangkun/git-repo,daimajia/git-repo,dodocat/git-repo,xianyo/git-repo,mixedpuppy/git-repo,jcfrank/myrepo,slfyusufu/repo,flingone/git-repo,ediTLJ/git-repo,biaolv/git-repo,linuxdeepin/git-repo,RuanJG/git-repo,aosp-mirror/tools_repo,codetutil/git-repo,eric011/git-repo,kangear/git-repo,slfyusufu/repo,xecle/git-repo,nuclearmistake/repo,ceejatec/git-repo,opencontrail-ci-admin/git-repo,hisilicon/git-repo,FuangCao/git-repo,11NJ/git-repo,eric011/git-repo,GatorQue/git-repo-flow,ChronoMonochrome/repo,lightsofapollo/git-repo,4455jkjh/repo,zemug/repo,hacker-camp/google_repo,chzhong/git-repo,hisilicon/git-repo,gabbayo/git-repo,lewixliu/git-repo,CyanogenMod/tools_repo