Remove nginx unix sockets

[aledbf]

What this PR does / why we need it:

The utilization of unix sockets in nginx is not possible when we try to mount an emptyDir volume. This is a requirement when a restrictive PodSecurityPolicy is defined (read-only fs).

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #4179

Special notes for your reviewer:

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf

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• OWNERS [aledbf]

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[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@76e2a5d). Click here to learn what that means.
The diff coverage is 62.5%.

@@            Coverage Diff            @@
##             master    #4531   +/-   ##
=========================================
  Coverage          ?   59.34%           
=========================================
  Files             ?       89           
  Lines             ?     6823           
  Branches          ?        0           
=========================================
  Hits              ?     4049           
  Misses            ?     2338           
  Partials          ?      436

Impacted Files	Coverage Δ
internal/ingress/controller/config/config.go	98.58% <ø> (ø)
internal/ingress/controller/nginx.go	29.44% <62.5%> (ø)

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