Fix of the chart.redis.port definition

[karloramone]

The function responsible for returning the chart.redis.port encounters an issue with its definition. When attempting to specify the port in the values, as demonstrated below:

externalRedis:
  host: kube-mail-redis
  port: "5555"

an error is encountered:

Error: template: kube-mail/templates/deployment.yaml:78:24: executing "kube-mail/templates/deployment.yaml" at <include "chart.redis.port" .>: error calling include: template: kube-mail/templates/_helpers.tpl:88:19: executing "chart.redis.port" at <.Values.redis.master.service.ports.redis>: nil pointer evaluating interface {}.service

This error arises because the ternary function expects both values to be defined, and then it selects one based on the test condition. However, .Values.redis.master.service.ports.redis is passed from the subchart only if .Values.redis.enabled is true, which is not the case here.