Fix mis-quoting in Redis hostname for Sidekiq/Unicorn

Found in #88 (closed)

The _helpers.tpl function for the Redis hostname quoted the hostname, however that resulted in invalid URI strings:

URL = "tcp://"gl-db":6379"
    
URI::InvalidURIError: bad URI(is not URI?): redis://:@"gl-db":6379

Clean those up, so that these charts work with external Redis hosts.

cc @marin @omame