fix nginx config location & improve setting paths
Replaces https://github.com/gitlabhq/gitlabhq/pull/8043 and https://github.com/gitlabhq/gitlabhq/pull/8069.
Make paths relative for ease of use, fix incorrect paths, & fix minor punctuation issues.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Replaces https://github.com/gitlabhq/gitlabhq/pull/8043 and https://github.com/gitlabhq/gitlabhq/pull/8069.
Make paths relative for ease of use, fix incorrect paths, & fix minor punctuation issues.