UDS listen sockets restrict VCL to >= 4.1
UDS listen sockets restrict VCL to >= 4.1

I had hoped for a more explanatory error message, but that is too
involved at this point.

gquintard/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache