[Expeditor] Use new template variables in .expeditor/config.yml
[Expeditor] Use new template variables in .expeditor/config.yml

You can now use `{{version_constraint}}` to reference the version
constraint for your release branch.

https://expeditor.chef.io/docs/getting-started/subscriptions/#subscription-template-variables

Signed-off-by: Tom Duffield <96835dd8bfa718bd6447ccc87af89ae1675daeca@chef.io>

martinisoft/chef,jaymzh/chef,gene1wood/chef,tas50/chef-1,mattray/chef,jaymzh/chef,martinisoft/chef,mattray/chef,higanworks/chef,higanworks/chef,mwrock/chef,MsysTechnologiesllc/chef,chef/chef,nvwls/chef,tas50/chef-1,Tensibai/chef,jaymzh/chef,gene1wood/chef,mattray/chef,chef/chef,mattray/chef,MsysTechnologiesllc/chef,higanworks/chef,tomdoherty/chef,mwrock/chef,martinisoft/chef,gene1wood/chef,tomdoherty/chef,MsysTechnologiesllc/chef,Tensibai/chef,tomdoherty/chef,Tensibai/chef,nvwls/chef,chef/chef,mattray/chef,tas50/chef-1,jaymzh/chef,mwrock/chef,tomdoherty/chef,nvwls/chef,tomdoherty/chef,martinisoft/chef,Tensibai/chef,tas50/chef-1,chef/chef,gene1wood/chef,nvwls/chef,higanworks/chef,nvwls/chef,higanworks/chef,nvwls/chef,martinisoft/chef,mwrock/chef,Tensibai/chef,MsysTechnologiesllc/chef