Include the serversnippet from the config map in server blocks

[ctriv]

…aliaes

What this PR does / why we need it:

The configmap server-snippet feature currently does not inject any directives into the server block.

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

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[k8s-reviewable]

This change is 

[coveralls]

Coverage remained the same at 33.492% when pulling 0aae811 on liquidweb:master into bf26abf on kubernetes:master.

[aledbf]

/lgtm

[aledbf]

@ctriv thanks!

[arunreddykaithe]

For my nginx-ingress conf. I only need server-snippet for default server {} module.
This should be optional, instead of hard-coding it to all server modules.

if you are passing only variables this makes sense. However, when a snippet with multiple lines of conditions is inserted. Having those conditions in multiple server modules is breaking stuff. And the only way content inside defaul server _( servername ;) is Server-snippet.

p.s : Having server-snippet option on default and all server modules - should have a flag/optional