Remove Puma notices from AdminArea banner
What does this MR do?
These two notices are removed:
You are running Puma, which is currently experimental. More information is available in our documentationPuma is running with a thread count above 1. Information on deprecated GitLab features in this configuration is available in the documentation
More background why they are removed:
Currently, we detect and display 3 messages(1st and 2nd are notices, the 3rd is a warning):
- Puma is the application server
- Puma multi-threaded(thread>1) in use
- Rugged enabled and multi-threaded(thread>1) Puma in use
Since most cases we expect Puma running with thread count > 1, so the 1st and 2nd messages will show:

The 2nd message(notice) is a bit redundant, because: for those users who are not using Rugged, we actually hope they use multi-threaded Puma(thread count > 1); for those users who are using Rugged, we will show the 3rd message.
The 1st message(notice) was there during Puma is experimental. Now we consider Puma is official since Gitlab.com switched to Puma. What is more, the linked-to documentation mainly talks about Rugged + multithread Puma. So it actually does not help much unless the deployment is Rugged + multi-thread Puma in which case the 3rd message(warning) will show anyway.
So the notices(1st and 2nd messages) are not necessary. This MR remove Puma notices from AdminArea banner