Revert "Add loggregator shared_secret property to config ymls"

This reverts commit 3971625406934ccaa1be4527f080a043015b9c86.

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#	modified:   jobs/cloud_controller_ng/templates/cloud_controller_ng.yml.erb
#	modified:   jobs/dea_next/templates/dea.yml.erb
#	modified:   jobs/gorouter/templates/gorouter.yml.erb
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