Fix up -o documentation for varnishlog
Fix up -o documentation for varnishlog

-o is needed for matching on tag/regex, the documentation did not make
 this clear.

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