/get/ returns a status code 200 even if the page does not exist

Reproduction steps:

• Assuming that the page XWiki/GetError404 does not exist
• Call the URL: http://localhost:8080/xwiki/bin/get/XWiki/GetError404

Expected result:

• The status code displayed in the network tab is 404

Obtained result:

• the status code is 200

This behaviour is error prone, as we can easily assume a request is working when debugging while it's actually not. On my case I found this while trying to understand why a live table was empty: would have been easier if I had seen right away the 404 error in the network tab.