Fix multiple tls hosts sharing the same secretName

[gianrubio]

The new controller changed the way that lookup for a ssl certificate. On the current ingress, on contrib, this tls mapping below works, but when I moved for this repo, some tls aren't generated.

    tls:
    - hosts:
      - aaaa.fake-domain.me
      secretName: auth.fake-domain.me
    - hosts:
      - nnnn.fake-domain.me
      secretName: cauth.fake-domain.me
    - hosts:
      - gggg.fake-domain.me
      secretName: gate.fake-domain.me
    - hosts:
      - my.fake-domain.me
      secretName: my.fake-domain.me
    - hosts:
      - rrrr.fake-domain.me
      - ppp.fake-domain.me
      - jjjj.fake-domain.me
      secretName: eu-fake-domain.me

[k8s-reviewable]

This change is 

[coveralls]

Coverage decreased (-0.03%) to 39.837% when pulling e033772 on gianrubio:fix-mutiple-tls into 3980756 on kubernetes:master.

[aledbf]

/lgtm

[k8s-ci-robot]

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In response to this comment:

/lgtm

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[aledbf]

/lgtm