Consul service tags list is error prone

[rgarrigue]

Hi there

This is my mistake for reading the doc too quickly, but vault_service_registration_consul_service_tags is a bit misleading : anyone could understand by the name it's a list of tag, hence

vault_service_registration_consul_service_tags:
  - this
  - that

Then boom

So maybe allow both format, or add an assert that'll break if it's an array instead of a string ?

Best regards,