Better handlig of proxy-server.conf location in Deploy/playbook/fetch_proxy_conf.yml

[ghost]

This YAML task does as follows:
Deploy/playbook/fetch_proxy_conf.yml
src=/tmp/proxy-server.conf dest=/etc/swift/proxy-server.conf

But this may not be where the conf file is, actually in a vagrant-swift it is definitely not !
We should have this as a configuration (one of the earlier points touches on this as well namely 9.