Warn not to use it in bgthreads.
Warn not to use it in bgthreads.

varnish/libvmod-cookie,varnish/libvmod-cookie,lkarsten/libvmod-cookie,ruckserve/libvmod-cookie,lkarsten/libvmod-cookie,ruckserve/libvmod-cookie,tricycle/libvmod-cookie,tricycle/libvmod-cookie,wjordan/libvmod-cookie,wjordan/libvmod-cookie