Revert "varnishtest: setuid(nobody) if running as root"
Revert "varnishtest: setuid(nobody) if running as root"

This had the unfortunate side effect of making builds in
non-world-readable directories not work correctly when run as root.

This reverts commit 07c4432ba55b50b6640c5eeb24155a3618224f61.

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