If parsing the manifests fails, reset the XmlManifest object
If parsing the manifests fails, reset the XmlManifest object

so that if it's called again, we see the correct errors.

Change-Id: I909488feeac04aecfc92a9b5d6fb17827ef2f213

cubieboard/git-repo,SunRain/repo,gabbayo/git-repo,Pankaj-Sakariya/android-source-browsing.git-repo,lipro-yocto/git-repo,nuclearmistake/repo,FlymeOS/repo,Pivosgroup/google-git-repo,slfyusufu/repo,duralog/repo,lewixliu/git-repo,couchbasedeps/git-repo,venus-solar/git-repo,linux-knight/repo,testbetta/repo-pub,TheQtCompany/git-repo,xyyangkun/git-repo,mixedpuppy/git-repo,dsiganos/git-repo,ceejatec/git-repo,4455jkjh/repo,ChronoMonochrome/repo,11NJ/git-repo,simbasailor/git-repo,dodocat/git-repo,aep/repo,CyanogenMod/tools_repo,mozilla/git-repo,eligoenergy/git-repo,mer-tools/git-repo,GatorQue/git-repo-flow,jingyu/git-repo,4455jkjh/repo,ediTLJ/git-repo,zemug/repo,Pankaj-Sakariya/android-source-browsing.git-repo,nbp/git-repo,FlymeOS/repo,duralog/repo,hisilicon/git-repo,dsiganos/git-repo,aep/repo,IbpTeam/repo,qupai/git-repo,FuangCao/repo,zbunix/git-repo,DavidPu/git-repo,GerritCodeReview/git-repo,nuclearmistake/repo,linuxdeepin/git-repo,mer-tools/git-repo,qupai/git-repo,baidurom/repo,windyan/git-repo,darrengarvey/git-repo,venus-solar/git-repo,cubieboard/git-repo,chzhong/git-repo,ThangBK2009/android-source-browsing.git-repo,vmx/git-repo,SaleJumper/android-source-browsing.git-repo,demonyangyue/git-repo,llg84/google_repo,testbetta/git-repo-pub,kangear/git-repo,daimajia/git-repo,ronan22/repo,gabbayo/git-repo,wzhy90/git-repo,ThangBK2009/android-source-browsing.git-repo,xecle/git-repo,darrengarvey/git-repo,hacker-camp/google_repo,loungin/git-repo,flingone/git-repo,wzhy90/git-repo,mixedpuppy/git-repo,eric011/git-repo,IbpTeam/repo,opencontrail-ci-admin/git-repo,kangear/git-repo,ronan22/repo,hisilicon/git-repo,biaolv/git-repo,dsiganos/git-repo,mozilla/git-repo,jcfrank/myrepo,FuangCao/git-repo,qioixiy/git-repo,linuxdeepin/git-repo,bhargavkumar040/android-source-browsing.git-repo,FuangCao/repo,xin3liang/git-repo,jcfrank/myrepo,aosp-mirror/tools_repo,ceejatec/git-repo,iAlios/git-repo,iAlios/git-repo,lightsofapollo/git-repo,eric011/git-repo,qioixiy/git-repo,GerritCodeReview/git-repo,opensourcechipspark/repo,gbraad/git-repo,xianyo/git-repo,wavecomp/git-repo,SaleJumper/android-source-browsing.git-repo,RuanJG/git-repo,DavidPu/git-repo,kdavis-mozilla/repo-repo,11NJ/git-repo,lshain/repo,vmx/git-repo,couchbasedeps/git-repo,opensourcechipspark/repo,windyan/git-repo,zbunix/git-repo,codetutil/git-repo,frogbywyplay/git-repo,loungin/git-repo,opencontrail-ci-admin/git-repo,xecle/git-repo,ChronoMonochrome/repo,testbetta/git-repo-pub,dodocat/git-repo,linux-knight/repo,petemoore/git-repo,chenzilin/git-repo,linux-knight/repo,baidurom/repo,wavecomp/git-repo,FuangCao/git-repo,GatorQue/git-repo-flow,lchiocca/repo,eligoenergy/git-repo,nbp/git-repo,codetutil/git-repo,xianyo/git-repo,lipro-yocto/git-repo,aosp-mirror/tools_repo,bhargavkumar040/android-source-browsing.git-repo,lchiocca/repo,biaolv/git-repo,RuanJG/git-repo,zemug/repo,derron/git-repo,xin3liang/git-repo,zbunix/git-repo,flingone/git-repo,TheQtCompany/git-repo,derron/git-repo,kdavis-mozilla/repo-repo,lightsofapollo/git-repo,frogbywyplay/git-repo,finik/git-repo,daimajia/git-repo,hacker-camp/google_repo,CyanogenMod/tools_repo,finik/git-repo,lshain/repo,ediTLJ/git-repo,simbasailor/git-repo,testbetta/repo-pub,gbraad/git-repo,chenzilin/git-repo,ilansmith/repo,llg84/google_repo,cubieboard/git-repo,chzhong/git-repo,aep/repo,Pivosgroup/google-git-repo,slfyusufu/repo,lewixliu/git-repo,petemoore/git-repo,jingyu/git-repo,SunRain/repo,demonyangyue/git-repo,xyyangkun/git-repo,finik/git-repo,ilansmith/repo