Allow VO-agnostic proxy certificate production

[Soap2G]

Communities that need to have a ftsRenewal daemon that creates proxies that are not registered in a VO (i.e. do voms-proxy-init without the --voms option, which is identical to grid-proxy-init), cannot do it.
Reasons are:

1. The default values in the chart are related to CMS
2. In order to declare RUCIO_FTS_VOMS in the the fts cronjob, we check for vo, so in general we always find something.
3. This means that when doing voms-proxy-init the variable RUCIO_FTS_VOMS always exists.