grace=0 should not mean "use default"
grace=0 should not mean "use default"

Spotted by:	Geoff

chrismoulton/Varnish-Cache,ajasty-cavium/Varnish-Cache,gauthier-delacroix/Varnish-Cache,mrhmouse/Varnish-Cache,ssm/pkg-varnish,zhoualbeart/Varnish-Cache,gauthier-delacroix/Varnish-Cache,zhoualbeart/Varnish-Cache,alarky/varnish-cache-doc-ja,franciscovg/Varnish-Cache,drwilco/varnish-cache-old,mrhmouse/Varnish-Cache,wikimedia/operations-debs-varnish,feld/Varnish-Cache,1HLtd/Varnish-Cache,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,drwilco/varnish-cache-drwilco,ssm/pkg-varnish,1HLtd/Varnish-Cache,feld/Varnish-Cache,feld/Varnish-Cache,mrhmouse/Varnish-Cache,ssm/pkg-varnish,alarky/varnish-cache-doc-ja,varnish/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,varnish/Varnish-Cache,1HLtd/Varnish-Cache,varnish/Varnish-Cache,franciscovg/Varnish-Cache,franciscovg/Varnish-Cache,gauthier-delacroix/Varnish-Cache,feld/Varnish-Cache,alarky/varnish-cache-doc-ja,drwilco/varnish-cache-drwilco,gauthier-delacroix/Varnish-Cache,ambernetas/varnish-cache,ambernetas/varnish-cache,drwilco/varnish-cache-drwilco,zhoualbeart/Varnish-Cache,drwilco/varnish-cache-old,varnish/Varnish-Cache,ssm/pkg-varnish,1HLtd/Varnish-Cache,mrhmouse/Varnish-Cache,alarky/varnish-cache-doc-ja,varnish/Varnish-Cache,chrismoulton/Varnish-Cache,chrismoulton/Varnish-Cache,ambernetas/varnish-cache,franciscovg/Varnish-Cache,franciscovg/Varnish-Cache,wikimedia/operations-debs-varnish,gauthier-delacroix/Varnish-Cache,ajasty-cavium/Varnish-Cache,gquintard/Varnish-Cache,ajasty-cavium/Varnish-Cache,ssm/pkg-varnish,ajasty-cavium/Varnish-Cache,gquintard/Varnish-Cache,alarky/varnish-cache-doc-ja,chrismoulton/Varnish-Cache,gquintard/Varnish-Cache,drwilco/varnish-cache-old,gquintard/Varnish-Cache,feld/Varnish-Cache,zhoualbeart/Varnish-Cache,wikimedia/operations-debs-varnish,mrhmouse/Varnish-Cache,ajasty-cavium/Varnish-Cache