systemd: Respect 'start' when following the journal
systemd: Respect 'start' when following the journal

If the initial query for old journal entries comes up empty, the
subsequent query that follows newly appearing entries should start at
the same place.

Closes #2146
Reviewed-by: Stef Walter <8a7fbf0f15d3ad982af54ef28f5c117d2494b76c@redhat.com>

garrett/cockpit,nmav/cockpit,SotolitoLabs/cockpit,garrett/cockpit,larskarlitski/cockpit,larskarlitski/cockpit,cockpituous/cockpit,xhad/cockpit,netzvieh/cockpit,Armstrong1992/cockpit,maxamillion/cockpit,sgallagher/cockpit,evol262/cockpit,nmav/cockpit,deryni/cockpit,Scribery/cockpit,firebitsbr/cockpit,garrett/cockpit,mvollmer/cockpit,andreasn/cockpit,evol262/cockpit,larskarlitski/cockpit,stefwalter/cockpit,netzvieh/cockpit,mareklibra/cockpit,cockpituous/cockpit,maxamillion/cockpit,haiyangd/cockpit_view,xhad/cockpit,FireDrunk/cockpit,vbatts/cockpit,Armstrong1992/cockpit,vanloswang/cockpit,denysvitali/cockpit,mvollmer/cockpit,dperpeet/cockpit,moraleslazaro/cockpit,michalskrivanek/cockpit,evol262/cockpit,Thermionix/cockpit,SotolitoLabs/cockpit,haiyangd/cockpit_view,petervo/cockpit,mareklibra/cockpit,arilivigni/cockpit,arilivigni/cockpit,Armstrong1992/cockpit,nmav/cockpit,deryni/cockpit,Scribery/cockpit,evol262/cockpit,harishanand95/cockpit,jscotka/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,deryni/cockpit,netzvieh/cockpit,matobet/cockpit,larskarlitski/cockpit,fridex/cockpit,deryni/cockpit,SotolitoLabs/cockpit,arilivigni/cockpit,larsu/cockpit,fridex/cockpit,michalskrivanek/cockpit,dperpeet/cockpit,vanloswang/cockpit,Scribery/cockpit,arilivigni/cockpit,andreasn/cockpit,FireDrunk/cockpit,petervo/cockpit,vbatts/cockpit,Thermionix/cockpit,andreasn/cockpit,jscotka/cockpit,mareklibra/cockpit,deryni/cockpit,zigitax/cockpit,cockpit-project/cockpit,larsu/cockpit,zigitax/cockpit,andreasn/cockpit,matobet/cockpit,larsu/cockpit,firebitsbr/cockpit,petervo/cockpit,dperpeet/cockpit,mareklibra/cockpit,harishanand95/cockpit,vanloswang/cockpit,arilivigni/cockpit,denysvitali/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,jscotka/cockpit,Scribery/cockpit,fridex/cockpit,fridex/cockpit,matobet/cockpit,darioajr/cockpit,mvollmer/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,jscotka/cockpit,FireDrunk/cockpit,cockpituous/cockpit,xhad/cockpit,fridex/cockpit,haiyangd/cockpit_view,moraleslazaro/cockpit,Scribery/cockpit,matobet/cockpit,vanloswang/cockpit,cockpit-project/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,haiyangd/cockpit_view,Thermionix/cockpit,moolitayer/cockpit,larskarlitski/cockpit,vbatts/cockpit,sgallagher/cockpit,xhad/cockpit,moraleslazaro/cockpit,vbatts/cockpit,moolitayer/cockpit,cockpit-project/cockpit,mareklibra/cockpit,vanloswang/cockpit,xhad/cockpit,FireDrunk/cockpit,dperpeet/cockpit,sgallagher/cockpit,matobet/cockpit,denysvitali/cockpit,larsu/cockpit,zigitax/cockpit,vanloswang/cockpit,petervo/cockpit,sgallagher/cockpit,matobet/cockpit,michalskrivanek/cockpit,darioajr/cockpit,dperpeet/cockpit,harishanand95/cockpit,firebitsbr/cockpit,mvollmer/cockpit,sgallagher/cockpit,sgallagher/cockpit,petervo/cockpit,dperpeet/cockpit,dperpeet/cockpit,vanloswang/cockpit,larsu/cockpit,Armstrong1992/cockpit,garrett/cockpit,martinpitt/cockpit,mareklibra/cockpit,xhad/cockpit,denysvitali/cockpit,netzvieh/cockpit,moolitayer/cockpit,cockpituous/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,stefwalter/cockpit,nmav/cockpit,larskarlitski/cockpit,deryni/cockpit,FireDrunk/cockpit,martinpitt/cockpit,sgallagher/cockpit,evol262/cockpit,Scribery/cockpit,maxamillion/cockpit,jscotka/cockpit,maxamillion/cockpit,cockpit-project/cockpit,deryni/cockpit,firebitsbr/cockpit,harishanand95/cockpit,SotolitoLabs/cockpit,darioajr/cockpit,Thermionix/cockpit,petervo/cockpit,moolitayer/cockpit,stefwalter/cockpit,michalskrivanek/cockpit,moolitayer/cockpit,zigitax/cockpit,vbatts/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,arilivigni/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,zigitax/cockpit,arilivigni/cockpit,denysvitali/cockpit,harishanand95/cockpit,vbatts/cockpit,evol262/cockpit,michalskrivanek/cockpit,cockpituous/cockpit,michalskrivanek/cockpit,firebitsbr/cockpit,darioajr/cockpit,xhad/cockpit,andreasn/cockpit,netzvieh/cockpit,harishanand95/cockpit,jscotka/cockpit,harishanand95/cockpit,Thermionix/cockpit,mareklibra/cockpit,larskarlitski/cockpit,larsu/cockpit,netzvieh/cockpit,garrett/cockpit,Scribery/cockpit,petervo/cockpit,Thermionix/cockpit,nmav/cockpit,andreasn/cockpit,fridex/cockpit,Armstrong1992/cockpit,cockpit-project/cockpit,darioajr/cockpit,mvollmer/cockpit,haiyangd/cockpit_view,maxamillion/cockpit,stefwalter/cockpit