doc: Fix bad JSON in rest-api.md
doc: Fix bad JSON in rest-api.md

Closes #3654

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

stgraber/lxd,pcdummy/lxd,pcdummy/lxd,atxwebs/lxd,Skarlso/lxd,mjeanson/lxd,mjeanson/lxd,lxc/lxd,erikmack/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,pcdummy/lxd,erikmack/lxd,mjeanson/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,hallyn/lxd,hallyn/lxd,jsavikko/lxd,jsavikko/lxd,hallyn/lxd,hallyn/lxd,atxwebs/lxd,Skarlso/lxd,hallyn/lxd,lxc/lxd,Skarlso/lxd,Skarlso/lxd,lxc/lxd,atxwebs/lxd,erikmack/lxd,jsavikko/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,lxc/lxd