Doc: add FAQ entry regarding Django's ALLOWED_HOSTS setting
Doc: add FAQ entry regarding Django's ALLOWED_HOSTS setting

This closes #626.

htem/CATMAID,htem/CATMAID,fzadow/CATMAID,fzadow/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID