TrivialRebase: Correctly handle empty patch-id
TrivialRebase: Correctly handle empty patch-id

If only one of the patch-ids is empty, it should not be
considered a trivial rebase

Change-Id: Ie5196bc81d4d3bcdd16572ade265f96c086fabed

Seinlin/gerrit,gerrit-review/gerrit,jackminicloud/test,gcoders/gerrit,jackminicloud/test,gerrit-review/gerrit,netroby/gerrit,Overruler/gerrit,basilgor/gerrit,jackminicloud/test,gracefullife/gerrit,gerrit-review/gerrit,thesamet/gerrit,dwhipstock/gerrit,WANdisco/gerrit,bpollack/gerrit,MerritCR/merrit,bpollack/gerrit,TonyChai24/test,ckamm/gerrit,MerritCR/merrit,renchaorevee/gerrit,Team-OctOS/host_gerrit,hdost/gerrit,netroby/gerrit,GerritCodeReview/gerrit,midnightradio/gerrit,anminhsu/gerrit,Seinlin/gerrit,netroby/gerrit,bootstraponline-archive/gerrit-mirror,netroby/gerrit,zommarin/gerrit,Overruler/gerrit,bootstraponline-archive/gerrit-mirror,midnightradio/gerrit,gerrit-review/gerrit,WANdisco/gerrit,joshuawilson/merrit,thinkernel/gerrit,gcoders/gerrit,Team-OctOS/host_gerrit,bpollack/gerrit,Team-OctOS/host_gerrit,anminhsu/gerrit,jackminicloud/test,quyixia/gerrit,quyixia/gerrit,supriyantomaftuh/gerrit,renchaorevee/gerrit,midnightradio/gerrit,MerritCR/merrit,gcoders/gerrit,GerritCodeReview/gerrit,renchaorevee/gerrit,GerritCodeReview/gerrit,supriyantomaftuh/gerrit,gracefullife/gerrit,bootstraponline-archive/gerrit-mirror,dwhipstock/gerrit,Overruler/gerrit,thinkernel/gerrit,TonyChai24/test,WANdisco/gerrit,TonyChai24/test,pkdevbox/gerrit,anminhsu/gerrit,anminhsu/gerrit,Seinlin/gerrit,zommarin/gerrit,Seinlin/gerrit,gerrit-review/gerrit,Distrotech/gerrit,thesamet/gerrit,jackminicloud/test,pkdevbox/gerrit,Team-OctOS/host_gerrit,pkdevbox/gerrit,thesamet/gerrit,TonyChai24/test,MerritCR/merrit,GerritCodeReview/gerrit,thinkernel/gerrit,ckamm/gerrit,bpollack/gerrit,gracefullife/gerrit,GerritCodeReview/gerrit,supriyantomaftuh/gerrit,dwhipstock/gerrit,GerritCodeReview/gerrit,dwhipstock/gerrit,anminhsu/gerrit,dwhipstock/gerrit,GerritCodeReview/gerrit,Team-OctOS/host_gerrit,MerritCR/merrit,thesamet/gerrit,thinkernel/gerrit,thinkernel/gerrit,bpollack/gerrit,basilgor/gerrit,Overruler/gerrit,renchaorevee/gerrit,hdost/gerrit,gcoders/gerrit,MerritCR/merrit,joshuawilson/merrit,qtproject/qtqa-gerrit,ckamm/gerrit,gcoders/gerrit,bootstraponline-archive/gerrit-mirror,supriyantomaftuh/gerrit,MerritCR/merrit,dwhipstock/gerrit,basilgor/gerrit,netroby/gerrit,Overruler/gerrit,dwhipstock/gerrit,quyixia/gerrit,qtproject/qtqa-gerrit,renchaorevee/gerrit,renchaorevee/gerrit,Saulis/gerrit,ckamm/gerrit,basilgor/gerrit,thesamet/gerrit,midnightradio/gerrit,bpollack/gerrit,renchaorevee/gerrit,qtproject/qtqa-gerrit,Distrotech/gerrit,hdost/gerrit,midnightradio/gerrit,quyixia/gerrit,Team-OctOS/host_gerrit,hdost/gerrit,thesamet/gerrit,GerritCodeReview/gerrit,joshuawilson/merrit,pkdevbox/gerrit,Distrotech/gerrit,supriyantomaftuh/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,WANdisco/gerrit,hdost/gerrit,quyixia/gerrit,gcoders/gerrit,qtproject/qtqa-gerrit,joshuawilson/merrit,pkdevbox/gerrit,zommarin/gerrit,Distrotech/gerrit,Seinlin/gerrit,hdost/gerrit,thinkernel/gerrit,Distrotech/gerrit,quyixia/gerrit,Seinlin/gerrit,gcoders/gerrit,Seinlin/gerrit,TonyChai24/test,WANdisco/gerrit,WANdisco/gerrit,Saulis/gerrit,supriyantomaftuh/gerrit,netroby/gerrit,gerrit-review/gerrit,anminhsu/gerrit,joshuawilson/merrit,midnightradio/gerrit,netroby/gerrit,pkdevbox/gerrit,bootstraponline-archive/gerrit-mirror,Saulis/gerrit,Saulis/gerrit,Saulis/gerrit,Distrotech/gerrit,Distrotech/gerrit,anminhsu/gerrit,joshuawilson/merrit,WANdisco/gerrit,zommarin/gerrit,jackminicloud/test,TonyChai24/test,thinkernel/gerrit,hdost/gerrit,supriyantomaftuh/gerrit,jackminicloud/test,Team-OctOS/host_gerrit,gracefullife/gerrit,pkdevbox/gerrit,joshuawilson/merrit,ckamm/gerrit,Overruler/gerrit,Saulis/gerrit,qtproject/qtqa-gerrit,gracefullife/gerrit,joshuawilson/merrit,thesamet/gerrit,MerritCR/merrit,zommarin/gerrit,gerrit-review/gerrit,basilgor/gerrit,bootstraponline-archive/gerrit-mirror,TonyChai24/test,quyixia/gerrit