Moved X-Auth-Request-Redirect back into correct location block for oa…

[kinghrothgar]

…uth2_proxy

What this PR does / why we need it:
This fixes an infinite sign in loop when using oauth2_proxy as external auth created by #1472 and discussed more in bitly/oauth2_proxy#427. More explanation can be found in the comment of my work mate here: #1472 (comment)

I'm not sure if this is the best way to fix this but we need some fix in so we can get it working.

[k8s-reviewable]

This change is 

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[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: kinghrothgar
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[coveralls]

Coverage remained the same at 39.742% when pulling aa770f56ac6b421ae6a988c2a812c91f2714043d on kinghrothgar:fixXAuthRequestRedirect into ad2238c on kubernetes:master.

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