Update vcap de-duplication rule
Update vcap de-duplication rule

Uses stop instead of ~ because Discard(~) is deprecated. 

http://www.rsyslog.com/doc/master/compatibility/v7compatibility.html#omruleset-and-discard-action-are-deprecated

[#155194490]
cloudfoundry/cf-deployment,emalm/cf-deployment,cloudfoundry/cf-deployment